Name…………………………………………
1
End of Chapter 7 HW
Alberto, Carlos and Maria share an inheritance of $54 000 in the ratio 3 : 4 : 5.
a What fraction of the money does Alberto get?
.........................................................................................................................[1 mark]
b Find the amount received by Alberto, Carlos and Maria
........................................................................................................................[3 marks]
c Alberto decides to divide his share between savings and investments. He saves $8100. What is
the ratio of savings to investments? Write your answer in its simplest terms.
........................................................................................................................[2 marks]
2
It takes 5 people 20 days to complete the repair of a stretch of road. How long will 8 people take?
....................................................................................................................... [2 marks]
3
A car uses fuel at the rate of 8.6 litres/100 km.
a How much fuel will it use to travel 650 km?
...............................................................................................................................[1 mark]
b How far can it travel on 5 litres of fuel?
.............................................................................................................................[2 marks]
4
Express each of the following ratios in its simplest form. [1 mark each]
b
64 : 24
d 5 minutes : 2 hours
......................................
5
......................................
e
1.5 kg : 750 g
.......................................
The speed of sound in dry air at 20°C is 343.2 metres per second. What is this speed in km/hour?
.......................................................................................................................[2 marks]
6
Mr Polski divides $27 pocket money between Anna and Jos in the ratio of their ages, 6 and 12.
a
7
Write the ratio in its simplest
form.
b
If Jos gets the greater share,
what fraction did he get?
c
How much did Anna get?
A panther can run at an average speed of 82 kilometres per hour (km/h).
If it runs at this speed for 3 hours 30 minutes, how far will it have run?
...................................................................................................................... [2 marks]
8
An aeroplane flies 3240 km in 5 hours. How far would it fly, at the same speed, in 9 hours?
9
................................................................................................................. [3 marks]
A scout leader bought 24 tins of beans for a total of $10.08 at the supermarket. How much will the
following cost her?
a
18 tins.............................................................................................................. [1 mark]
b
72 tins.............................................................................................................. [1 mark]
Name…………………………………………
End of Chapter 7 HW
10 Mr Van Klost travels from Frankfurt to Fritzlar, a distance of 158 km.
a
If his average speed is 88 km/h, how long does the journey take?
....................................................................................................................... [1 mark]
b
He does the return journey in 90 minutes. What is his average speed for this journey?
........................................................................................................................ [1 mark]
11 1.5 m3 of concrete is made using 540 kg of cement, 1728 kg of stone, 1026 kg of sand and 249 litres of water.
How much of each ingredient is needed to make enough concrete to fill 8 m3 of foundations?
...............................................................................................................................
..................................................................................................................... [3 marks]
12 A house plan is drawn to a scale of 1 : 50.
a
The kitchen is 8 cm wide on the plan. What is the actual width of the kitchen, in metres?
....................................................................................................................... [1 mark]
b
If the conservatory is 4.5 m wide by 5.7 m long, what will its size be on the drawing, in centimetres?
....................................................................................................................... [1 mark]
13 A restaurant has orders for pasta, fish and steak in the ratio 5 : 4 : 3. They run out of fish, so three-quarters
of those who ordered fish change their order to steak, and the rest change to pasta.
What is the ratio of pasta to steak orders now?
...............................................................................................................................
...................................................................................................................... [2 marks]
14 A tortoise starts to cross a field at exactly 8.00 am at a speed of 2 metres per minute. A hare
9.30 am and heads towards the tortoise at a speed of 60 metres per minute.
a
starts at
How far apart will the hare and the tortoise be at 9.33 am?
....................................................................................................................... [1 mark]
b
Will the hare have passed the tortoise at 9.33 am?
....................................................................................................................... [1 mark]
15 The space shuttle orbits the Earth at a speed of 27 800 kilometres per hour
(km/h) and travels 42 160 kilometres on each orbit. Ratna sees it pass overhead
at 8:15 pm one evening.
When should she expect to see it overhead again on its next orbit? [3 marks]
16 p varies directly with q.
Find the missing value in this table.
p
6
q
15
20
17 The mass (M) of a steel rod varies directly with the
length (L). Find the missing mass in this table.
L
M
64.0
80.0
72.0