Cambridge International Mathematics

Assumed Knowledge (Number) 15

Example 20 Self Tutor

Express45 : 10 in simplest form.

45 : 10

=45¥ 5 :10¥ 5 f 5 is the HCF of 45 and 10 g

=9:2

Example 21 Self Tutor

Express in simplest form:

a 0 :4:1: 4 b 212 :^12

a 0 :4:1: 4

=0: 4 £ 10 :1: 4 £ 10

=4:14

=4¥ 2 :14¥ 2

=2:7

b 212 :^12

=^52 :^12

=^52 £ 2 :^12 £ 2

=5:1

1 Express as a ratio in simplest form:

a 6:8 b 8:4 c 4:12 d 9:15

e 3:6 f 14 : 8 g 8:16 h 18 : 24

i 125 : 100 j 2:4:6 k 1000 : 50 l 6 : 12 : 24

2 Express as a ratio in simplest form:

a 0 :5:0: 2 b 0 :3:0: 7 c 0 :6:0: 4 d 0 :4:0: 2

e 0 :7:1: 2 f 0 :03 : 0: 12 g 2:0: 5 h 0 :05 : 1

3 Express as a ratio in simplest form:

a^13 :^23 b^34 :^14 c 112 :^12 d 112 :2^12

e^13 :^12 f 113 :2^12 g^23 :3^14 h 1103 :1^23

i 113 :^23 j^34 :1^12 k 6:1^12 l^12 :^13 :^14

4 Write the following comparisons as ratios in simplest form. Compare the first quantity mentioned with

the second quantity mentioned.

a a shirt costingE 64 to another shirt costingE 32

b a rockmelon of mass 3 kg to a watermelon of mass 9 kg

c the height of a 1. 5 m shrub to the height of a 6 m tree

d a wetsuit costing$175to a wetsuit costing$250

e the top speed of a car which is 150 km/h to the top speed of a formula one car which is 350 km/h

f a log of length 4 m to a stick of length 10 cm

g the height of an insect which is 2 mm to the height of a rat which is 10 cm.

EXERCISE F.2

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