level 8
Ks3 Revision work Level 8 1.
More powers Look at this information.
y2
=
10
Use the information to write numbers in the boxes below.
y4
= 1 mark
y
=
1000 1 mark
2.
Pythagoras The triangles in this question are not drawn accurately. (a)
Use Pythagoras’ theorem to explain why triangle A must be right-angled.
10 cm A
6 cm
8 cm 1 mark
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1
(b)
Triangle A is enlarged to make triangle B. Use similar triangles to show that d = 9.2 cm.
6.9 cm
B
d 1 mark
(c)
The diagram shows the Earth and two other planets. Planet P is 6.9 × 107km from Earth. Planet Q is 9.2 × 107km from Earth. Planet P
6.9 × 10 7 km
Planet Q
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9.2 × 10 7 km
Earth
2
How far is Planet P from Planet Q? Give your answer in standard form.
.............................km 2 marks
3.
Gorillas Here is part of a newspaper report about wildlife in a country in Africa.
The number of gorillas has fallen by 70% in the last ten years. Only about 5000 gorillas are left.
About how many gorillas were there in this country ten years earlier?
............................... 2 marks
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3
4.
Equation Look at this equation.
y
(a)
60 x – 10
Find y when x 19 There are two answers. Write them both.
y = ......................... or
y = ......................... 1 mark
(b)
You cannot find a value for y when x 10 Explain why not.
1 mark
(c)
There are other values of x for which you cannot find a value for y Give one such value of x
x = ......................... 1 mark
Hertfordshire La Schools
4
5.
Perimeters The perimeter of the triangle drawn on the square grid is (2 +
2 ) cm.
2
1 1
(a)
On the square grid below, draw a triangle with a perimeter of 3(2 +
2 ) cm.
1 mark
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5
(b)
On the square grid below, draw a shape with a perimeter of (2 + 3 2 ) cm.
1 mark
6.
Thinking diagonally The diagram shows a square with side length 5 cm.
Not drawn accurately
y cm
(a)
The length of the diagonal is y cm. Show that the value of y is
50
1 mark
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6
(b)
The square is enlarged by a scale factor of 2 Which value below shows the length of the diagonal of the enlarged square?
100
200
Explain your answer.
1 mark
7.
Expressions (a)
This solid is a prism, with height 3x. The cross-section is shaded.
4x
2x
3x
2x
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x NOT TO SCALE
7
Write an expression for the volume of the solid. Show your working and simplify your expression.
2 marks
The volume of this prism is given by the expression 8x3 sin a
2x
a x 4x
(b)
NOT TO SCALE
What value of a would make the volume of the prism 8x3?
1 mark
a ..........................°
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8
The prism has a volume of 500cm3. The value of a is 30
(c)
What is the value of x? Show your working.
x ......................... cm 2 marks
8.
Farm 40 students worked on a farm one weekend. The cumulative frequency graph shows the distribution of the amount of money they earned. No one earned less than £15.
40
30
Cumulative 20 Frequency
10
0 0
5
10
15
20
25
30
35
40
45
50
Amount of money earned (£)
Hertfordshire La Schools
9
(a)
Read the graph to estimate the median amount of money earned.
Median £ .............................. 1 mark
(b)
Estimate the percentage of students who earned less than £40.
.............................. % 1 mark
(c)
Show on the graph how to work out the interquartile range of the amount of money earned. Write down the value of the interquartile range.
Interquartile range £ .............................. 1 mark
(d)
30 of the students work on the farm another weekend later in the year. The tables below show the distribution of the amount of money earned by the students.
Money earned (£)
No. of students
> 25 and < 30
1
> 30 and < 35
2
> 35 and < 40
3
> 40 and < 45
4
> 45 and < 50
10
> 50 and < 55
7
> 55 and < 60
3
Hertfordshire La Schools
Money earned (£)
No. of students
< 25
0
< 30
1
< 35
3
< 40
6
< 45
10
< 50
20
< 55
27
< 60
30
10
Draw a cumulative frequency graph using the axes below.
30
Cumulative frequency
25
20
15
10
5
0 5
0
10
15
20 25 30 35 40 45 Amount of money earned (£)
50
55
60 2 marks
(e)
Put a by any statement below which is true. Put a x by any statement below which is false.
A.
Three of the students earned less than £35 each. ..............................
B.
The median amount earned is between £40 and £45. ........................
C.
Most of the 30 students earned more than £50 each. ......................... 1 mark
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11
9.
Solving x Look at the diagram:
A
D xº 3xº
B
C
NOT TO SCALE
Side AB is the same length as side AC. Side BD is the same length as side BC.
Calculate the value of x Show your working.
x ............................... 2 marks
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12
10.
Field voles Field voles are small animals that do not live for very long. A scientist recorded data on 1000 of these voles that were born on the same day. The graph shows how many voles were still alive after a number of weeks. 1000 900 800 700 Number of voles still alive
600 500 400 300 200 100 0 0
10
20
30
40
50
60
70
80
90
100
Use the graph to answer these questions. (a)
Estimate the probability that a field vole will live to be at least 20 weeks old. ............................... 1 mark
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13
(b)
A field vole is 40 weeks old. Estimate the probability that it will live to be at least 50 weeks old. ............................... 1 mark
11.
Light years (a)
One light year is approximately 9 430 000 000 000 kilometres. Write this distance in standard form.
.......................... km 1 mark
(b)
A star called Wolf 359 is approximately 7.8 light years from Earth. About how many kilometres is this? Write your answer in standard form.
.......................... km 1 mark
12.
Households A housing report gave this information. In the year 2001, the population of England was 49.87 million people. Most of these people lived in households. The total number of households was 20.97 million. The average (mean) household size was 2.34 people.
Hertfordshire La Schools
14
In the year 2001, what percentage of people in England did not live in households? Give your answer to 1 decimal place.
............................% 3 marks
Hertfordshire La Schools
15
13.
Triangle The diagram shows a triangle. Side XY is of length 11b Side XZ is of length 2a + 3b Side YZ is of length a
X
11b
Y
2a + 3b
a
Z
The triangle is isosceles, with XY XZ The perimeter of the triangle is 91
Use algebra to find the values of a and b
a ...................
b .................. 3 marks
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16
14.
Acorns Two groups of pupils collected a sample of acorns from the same oak tree. The box plots summarise the two sets of results.
Group A Group B
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Length (mm)
(a)
Explain how the box plots show the median of group B is 3 mm more than the median of group A.
1 mark
(b)
Which group has the bigger inter-quartile range? A
B
Explain your answer.
1 mark
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17
(c)
The results from the two groups of pupils are very different. Give a reason why the results might have been different.
1 mark
15.
Three dice I have three fair dice, each numbered 1 to 6
I am going to throw all three dice. What is the probability that all three dice will show the same number?
Hertfordshire La Schools
18
2 marks
16.
Angle proof The diagram shows 3 points, A, B and C, on a circle, centre O. AC is a diameter of the circle.
B
C
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x°
y° O
A
19
(a)
Angle BAO is x and angle BCO is y Explain why angle ABO must be x and angle CBO must be y
1 mark
(b)
Use algebra to show that angle ABC must be 90
1 mark
Hertfordshire La Schools
20
17.
Journeys This question is about a journey between two towns that are 100 km apart. When the journey time is 2 hours, the average speed is 50 km/h. The journey time is different at different average speeds. Show the relationship between journey time and average speed by drawing a graph on the grid below. 100 90 80 70 60 Average speed (km/h)
50 40 30 20 10 0 0
1
2
3
4
5
6
7
8
9
10
Journey times (hours) 3 marks
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21
18.
Tests 5000 pupils took part in a test. Pupils took two papers, paper 1 and paper 2. The graph shows the cumulative frequencies of their marks for each paper.
Hertfordshire La Schools
22
Use the graph to answer these questions. For each question tick ( ) True, or False, or Not enough information.
(a)
The median mark for paper 1 was about 38
True
False
Not enough information
Explain your answer.
1 mark
(b)
The inter-quartile range of the marks for paper 1 was about 23
True
False
Not enough information
Explain your answer.
1 mark
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23
(c)
Paper 1 was easier than paper 2.
True
False
Not enough information
Explain your answer.
1 mark
19.
Tiles A pupil has three tiles. One is a regular octagon, one is a regular hexagon, and one is a square. The side length of each tile is the same. The pupil says the hexagon will fit exactly like this.
Not drawn accurately
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24
Show calculations to prove that the pupil is wrong.
3 marks
20.
Increases by 3 For each equation below, when x increases by 3, what happens to y? Complete the sentences.
y=x When x increases by 3, y increases by................
y = 2x When x increases by 3, y increases by................
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25
y = 3x + 1 When x increases by 3, y increases by................ 2 marks
21.
Births The table shows data about births in the UK.
(a)
Year
Number of births
1910
1.05 × 106
1920
1.13 × 106
1930
7.69 × 105
1940
7.02 × 105
1950
8.18 × 105
1960
9.18 × 105
1970
9.04 × 105
1980
7.54 × 105
1990
7.99 × 105
In which year was the number of births the highest?
............................... 1 mark
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26
(b)
How many more births were there in 1990 than in 1980? Show your working and write your answer in standard form.
............................... 2 marks
22.
Octagon Look at this octagon:
y C
D
-10
B
A
5
-5
0
5
-5
E F
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10
-10
10
x
H G
27
(a)
The line through A and H has the equation x 10. What is the equation of the line through F and G?
.................................. 1 mark
(b)
Fill in the gaps below:
x + y 15 is the equation of the line through .................... and .................. 1 mark
(c)
The octagon has four lines of symmetry. One of the lines of symmetry has the equation y = x On the diagram, draw and label the line y = x 1 mark
(d)
The octagon has three other lines of symmetry. Write the equation of one of these three other lines of symmetry.
................................. 1 mark
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28
(e)
The line through D and B has the equation 3y x + 25 The line through G and H has the equation x y + 15 C
B
D
A
E
H F
G
Solve the simultaneous equations 3y x + 25
x y + 15 Show your working.
x ............................... y ............................... 2 marks
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29
(f)
Complete this sentence: The line through D and B meets the line through G and H at ( ..........., ............ ) 1 mark
23.
Expressions Look at the equation in the box.
+
x =
(x + 1)
+
(x + 2)
y
Use it to help you write the missing expressions in terms of y The first one is done for you.
5
+
x
+
(x + 1)
+
(x + 2)
=
(x + 5)
+
(x + 6)
+
(x + 7)
=
+ 2(x + 1)
+ 2(x + 2)
=
+ (x + 1 + a)
+ (x + 2 + a)
=
2x (x + a)
y5 ......................
...................... ...................... ...................... 2 marks
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30
24.
Tanks On a farm many years ago the water tanks were filled using a bucket from a well. (a)
The table shows the numbers of buckets, of different capacities, needed to fill a tank of capacity 2400 pints. Complete the table:
Capacity of bucket (pints) Number of buckets
(b)
8
10
12
200
15
16
150
100
80
Write an equation using symbols to connect T, the capacity of the tank, B, the capacity of a bucket, and N, the number of buckets.
1 mark
(c)
Now tanks are filled through a hosepipe connected to a tap. The rate of flow through the hosepipe can be varied. The tank of capacity 4000 litres fills at a rate of 12.5 litres per minute. How long in hours and minutes does it take to fill the tank? Show your working.
............... hours ............... minutes 2 marks
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(d)
Another tank took 5 hours to fill at a different rate of flow. How long would it have taken to fill this tank if this rate of flow had been increased by 100%?
............... hours ............... minutes 1 mark
(e)
How long would it have taken to fill this tank if the rate of low had been increased by only 50%? Show your working.
............... hours ............... minutes 2 marks
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(f)
This tank, measuring a by b by c, takes 1 hour 15 minutes to fill.
c a
b
How long does it take to fill 2a by 2b by 2c, at the same rate of flow?
2c 2a 2b Show your working.
2 marks
25.
Storm Speed of light is about
1.1 × 109 km per hour
Speed of sound is about 1.2 × 103 km per hour
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(a)
Calculate the speed of light in km per second. Give your answer in standard form. Show your working.
.............................. km per second 2 marks
(b)
How many times as fast as the speed of sound is the speed of light? Give your answer to an appropriate degree of accuracy. Show your working.
2 marks
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34
(c)
Gary sees a flash of lightning. 25 second later he hears the sound of thunder. Calculate how far away he is from the lightning. (You do not need to include the speed of light in your calculation). Show your working.
.............................. km 2 marks
Hertfordshire La Schools
35
More powers Look at this information.
y2
=
10
Use the information to write numbers in the boxes below.
y4
= 1 mark
y
=
1000 1 mark
2.
Pythagoras The triangles in this question are not drawn accurately. (a)
Use Pythagoras’ theorem to explain why triangle A must be right-angled.
10 cm A
6 cm
8 cm 1 mark
Hertfordshire La Schools
1
(b)
Triangle A is enlarged to make triangle B. Use similar triangles to show that d = 9.2 cm.
6.9 cm
B
d 1 mark
(c)
The diagram shows the Earth and two other planets. Planet P is 6.9 × 107km from Earth. Planet Q is 9.2 × 107km from Earth. Planet P
6.9 × 10 7 km
Planet Q
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9.2 × 10 7 km
Earth
2
How far is Planet P from Planet Q? Give your answer in standard form.
.............................km 2 marks
3.
Gorillas Here is part of a newspaper report about wildlife in a country in Africa.
The number of gorillas has fallen by 70% in the last ten years. Only about 5000 gorillas are left.
About how many gorillas were there in this country ten years earlier?
............................... 2 marks
Hertfordshire La Schools
3
4.
Equation Look at this equation.
y
(a)
60 x – 10
Find y when x 19 There are two answers. Write them both.
y = ......................... or
y = ......................... 1 mark
(b)
You cannot find a value for y when x 10 Explain why not.
1 mark
(c)
There are other values of x for which you cannot find a value for y Give one such value of x
x = ......................... 1 mark
Hertfordshire La Schools
4
5.
Perimeters The perimeter of the triangle drawn on the square grid is (2 +
2 ) cm.
2
1 1
(a)
On the square grid below, draw a triangle with a perimeter of 3(2 +
2 ) cm.
1 mark
Hertfordshire La Schools
5
(b)
On the square grid below, draw a shape with a perimeter of (2 + 3 2 ) cm.
1 mark
6.
Thinking diagonally The diagram shows a square with side length 5 cm.
Not drawn accurately
y cm
(a)
The length of the diagonal is y cm. Show that the value of y is
50
1 mark
Hertfordshire La Schools
6
(b)
The square is enlarged by a scale factor of 2 Which value below shows the length of the diagonal of the enlarged square?
100
200
Explain your answer.
1 mark
7.
Expressions (a)
This solid is a prism, with height 3x. The cross-section is shaded.
4x
2x
3x
2x
Hertfordshire La Schools
x NOT TO SCALE
7
Write an expression for the volume of the solid. Show your working and simplify your expression.
2 marks
The volume of this prism is given by the expression 8x3 sin a
2x
a x 4x
(b)
NOT TO SCALE
What value of a would make the volume of the prism 8x3?
1 mark
a ..........................°
Hertfordshire La Schools
8
The prism has a volume of 500cm3. The value of a is 30
(c)
What is the value of x? Show your working.
x ......................... cm 2 marks
8.
Farm 40 students worked on a farm one weekend. The cumulative frequency graph shows the distribution of the amount of money they earned. No one earned less than £15.
40
30
Cumulative 20 Frequency
10
0 0
5
10
15
20
25
30
35
40
45
50
Amount of money earned (£)
Hertfordshire La Schools
9
(a)
Read the graph to estimate the median amount of money earned.
Median £ .............................. 1 mark
(b)
Estimate the percentage of students who earned less than £40.
.............................. % 1 mark
(c)
Show on the graph how to work out the interquartile range of the amount of money earned. Write down the value of the interquartile range.
Interquartile range £ .............................. 1 mark
(d)
30 of the students work on the farm another weekend later in the year. The tables below show the distribution of the amount of money earned by the students.
Money earned (£)
No. of students
> 25 and < 30
1
> 30 and < 35
2
> 35 and < 40
3
> 40 and < 45
4
> 45 and < 50
10
> 50 and < 55
7
> 55 and < 60
3
Hertfordshire La Schools
Money earned (£)
No. of students
< 25
0
< 30
1
< 35
3
< 40
6
< 45
10
< 50
20
< 55
27
< 60
30
10
Draw a cumulative frequency graph using the axes below.
30
Cumulative frequency
25
20
15
10
5
0 5
0
10
15
20 25 30 35 40 45 Amount of money earned (£)
50
55
60 2 marks
(e)
Put a by any statement below which is true. Put a x by any statement below which is false.
A.
Three of the students earned less than £35 each. ..............................
B.
The median amount earned is between £40 and £45. ........................
C.
Most of the 30 students earned more than £50 each. ......................... 1 mark
Hertfordshire La Schools
11
9.
Solving x Look at the diagram:
A
D xº 3xº
B
C
NOT TO SCALE
Side AB is the same length as side AC. Side BD is the same length as side BC.
Calculate the value of x Show your working.
x ............................... 2 marks
Hertfordshire La Schools
12
10.
Field voles Field voles are small animals that do not live for very long. A scientist recorded data on 1000 of these voles that were born on the same day. The graph shows how many voles were still alive after a number of weeks. 1000 900 800 700 Number of voles still alive
600 500 400 300 200 100 0 0
10
20
30
40
50
60
70
80
90
100
Use the graph to answer these questions. (a)
Estimate the probability that a field vole will live to be at least 20 weeks old. ............................... 1 mark
Hertfordshire La Schools
13
(b)
A field vole is 40 weeks old. Estimate the probability that it will live to be at least 50 weeks old. ............................... 1 mark
11.
Light years (a)
One light year is approximately 9 430 000 000 000 kilometres. Write this distance in standard form.
.......................... km 1 mark
(b)
A star called Wolf 359 is approximately 7.8 light years from Earth. About how many kilometres is this? Write your answer in standard form.
.......................... km 1 mark
12.
Households A housing report gave this information. In the year 2001, the population of England was 49.87 million people. Most of these people lived in households. The total number of households was 20.97 million. The average (mean) household size was 2.34 people.
Hertfordshire La Schools
14
In the year 2001, what percentage of people in England did not live in households? Give your answer to 1 decimal place.
............................% 3 marks
Hertfordshire La Schools
15
13.
Triangle The diagram shows a triangle. Side XY is of length 11b Side XZ is of length 2a + 3b Side YZ is of length a
X
11b
Y
2a + 3b
a
Z
The triangle is isosceles, with XY XZ The perimeter of the triangle is 91
Use algebra to find the values of a and b
a ...................
b .................. 3 marks
Hertfordshire La Schools
16
14.
Acorns Two groups of pupils collected a sample of acorns from the same oak tree. The box plots summarise the two sets of results.
Group A Group B
20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 Length (mm)
(a)
Explain how the box plots show the median of group B is 3 mm more than the median of group A.
1 mark
(b)
Which group has the bigger inter-quartile range? A
B
Explain your answer.
1 mark
Hertfordshire La Schools
17
(c)
The results from the two groups of pupils are very different. Give a reason why the results might have been different.
1 mark
15.
Three dice I have three fair dice, each numbered 1 to 6
I am going to throw all three dice. What is the probability that all three dice will show the same number?
Hertfordshire La Schools
18
2 marks
16.
Angle proof The diagram shows 3 points, A, B and C, on a circle, centre O. AC is a diameter of the circle.
B
C
Hertfordshire La Schools
x°
y° O
A
19
(a)
Angle BAO is x and angle BCO is y Explain why angle ABO must be x and angle CBO must be y
1 mark
(b)
Use algebra to show that angle ABC must be 90
1 mark
Hertfordshire La Schools
20
17.
Journeys This question is about a journey between two towns that are 100 km apart. When the journey time is 2 hours, the average speed is 50 km/h. The journey time is different at different average speeds. Show the relationship between journey time and average speed by drawing a graph on the grid below. 100 90 80 70 60 Average speed (km/h)
50 40 30 20 10 0 0
1
2
3
4
5
6
7
8
9
10
Journey times (hours) 3 marks
Hertfordshire La Schools
21
18.
Tests 5000 pupils took part in a test. Pupils took two papers, paper 1 and paper 2. The graph shows the cumulative frequencies of their marks for each paper.
Hertfordshire La Schools
22
Use the graph to answer these questions. For each question tick ( ) True, or False, or Not enough information.
(a)
The median mark for paper 1 was about 38
True
False
Not enough information
Explain your answer.
1 mark
(b)
The inter-quartile range of the marks for paper 1 was about 23
True
False
Not enough information
Explain your answer.
1 mark
Hertfordshire La Schools
23
(c)
Paper 1 was easier than paper 2.
True
False
Not enough information
Explain your answer.
1 mark
19.
Tiles A pupil has three tiles. One is a regular octagon, one is a regular hexagon, and one is a square. The side length of each tile is the same. The pupil says the hexagon will fit exactly like this.
Not drawn accurately
Hertfordshire La Schools
24
Show calculations to prove that the pupil is wrong.
3 marks
20.
Increases by 3 For each equation below, when x increases by 3, what happens to y? Complete the sentences.
y=x When x increases by 3, y increases by................
y = 2x When x increases by 3, y increases by................
Hertfordshire La Schools
25
y = 3x + 1 When x increases by 3, y increases by................ 2 marks
21.
Births The table shows data about births in the UK.
(a)
Year
Number of births
1910
1.05 × 106
1920
1.13 × 106
1930
7.69 × 105
1940
7.02 × 105
1950
8.18 × 105
1960
9.18 × 105
1970
9.04 × 105
1980
7.54 × 105
1990
7.99 × 105
In which year was the number of births the highest?
............................... 1 mark
Hertfordshire La Schools
26
(b)
How many more births were there in 1990 than in 1980? Show your working and write your answer in standard form.
............................... 2 marks
22.
Octagon Look at this octagon:
y C
D
-10
B
A
5
-5
0
5
-5
E F
Hertfordshire La Schools
10
-10
10
x
H G
27
(a)
The line through A and H has the equation x 10. What is the equation of the line through F and G?
.................................. 1 mark
(b)
Fill in the gaps below:
x + y 15 is the equation of the line through .................... and .................. 1 mark
(c)
The octagon has four lines of symmetry. One of the lines of symmetry has the equation y = x On the diagram, draw and label the line y = x 1 mark
(d)
The octagon has three other lines of symmetry. Write the equation of one of these three other lines of symmetry.
................................. 1 mark
Hertfordshire La Schools
28
(e)
The line through D and B has the equation 3y x + 25 The line through G and H has the equation x y + 15 C
B
D
A
E
H F
G
Solve the simultaneous equations 3y x + 25
x y + 15 Show your working.
x ............................... y ............................... 2 marks
Hertfordshire La Schools
29
(f)
Complete this sentence: The line through D and B meets the line through G and H at ( ..........., ............ ) 1 mark
23.
Expressions Look at the equation in the box.
+
x =
(x + 1)
+
(x + 2)
y
Use it to help you write the missing expressions in terms of y The first one is done for you.
5
+
x
+
(x + 1)
+
(x + 2)
=
(x + 5)
+
(x + 6)
+
(x + 7)
=
+ 2(x + 1)
+ 2(x + 2)
=
+ (x + 1 + a)
+ (x + 2 + a)
=
2x (x + a)
y5 ......................
...................... ...................... ...................... 2 marks
Hertfordshire La Schools
30
24.
Tanks On a farm many years ago the water tanks were filled using a bucket from a well. (a)
The table shows the numbers of buckets, of different capacities, needed to fill a tank of capacity 2400 pints. Complete the table:
Capacity of bucket (pints) Number of buckets
(b)
8
10
12
200
15
16
150
100
80
Write an equation using symbols to connect T, the capacity of the tank, B, the capacity of a bucket, and N, the number of buckets.
1 mark
(c)
Now tanks are filled through a hosepipe connected to a tap. The rate of flow through the hosepipe can be varied. The tank of capacity 4000 litres fills at a rate of 12.5 litres per minute. How long in hours and minutes does it take to fill the tank? Show your working.
............... hours ............... minutes 2 marks
Hertfordshire La Schools
31
(d)
Another tank took 5 hours to fill at a different rate of flow. How long would it have taken to fill this tank if this rate of flow had been increased by 100%?
............... hours ............... minutes 1 mark
(e)
How long would it have taken to fill this tank if the rate of low had been increased by only 50%? Show your working.
............... hours ............... minutes 2 marks
Hertfordshire La Schools
32
(f)
This tank, measuring a by b by c, takes 1 hour 15 minutes to fill.
c a
b
How long does it take to fill 2a by 2b by 2c, at the same rate of flow?
2c 2a 2b Show your working.
2 marks
25.
Storm Speed of light is about
1.1 × 109 km per hour
Speed of sound is about 1.2 × 103 km per hour
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(a)
Calculate the speed of light in km per second. Give your answer in standard form. Show your working.
.............................. km per second 2 marks
(b)
How many times as fast as the speed of sound is the speed of light? Give your answer to an appropriate degree of accuracy. Show your working.
2 marks
Hertfordshire La Schools
34
(c)
Gary sees a flash of lightning. 25 second later he hears the sound of thunder. Calculate how far away he is from the lightning. (You do not need to include the speed of light in your calculation). Show your working.
.............................. km 2 marks
Hertfordshire La Schools
35
