Cambridge International Mathematics

20 Assumed Knowledge (Number)

7 Divide an inheritance of$36 000in the ratio 3:5:10.

8

a sugar b cocoa is used?

9 At the moorings on a river, there are yachts, motorboats,

houseboats and rowboats.

The ratio of yachts : motorboats : houseboats is4:5:3.

If there are 50 watercraft on the river and two of them are

rowboats, how many are:

a yachts b motorboats c houseboats?

Consider the decimal number 0 : 75.

We can write it as a fraction, since 0 :75 = 10075 =^34.

We can also write it as the ratio 3:4, or as a percentage since 0 : 75 £100% = 75%.

So, 0 : 75 ,^34 , 3:4and 75% are allequivalent.

It is important that you can convert between these different forms of numbers.

Example 28 Self Tutor

Copy and complete: Decimal Fraction Ratio Percentage

a^25

b 3:2

c 68%

d 0 : 875

a^25 = 104 =0: 4

2

5 is the ratio 2:5

2

5 £100% = 40%

b 3:2is the fraction^32

3

2 =3¥2=1:^5

3

2 £100% = 150%

c 68% = 10068 =0: 68

68

100 =

17

25

17

25 is the ratio 17 : 25

d 0 :875 = 1000875 =^78

7

8 is the ratio 7:8

875

1000 =

87 : 5

100 =87:5%

Decimal Fraction Ratio Percentage

a 0 : 4 25 2:5 40%

b 1 : 5 32 3:2 150%

c 0 : 68 1725 17 : 25 68%

d 0 : 875 78 7:8 87 :5%

G NUMBER EQUIVALENTS [1.7]

The ratio of flour sugar cocoa in a cake recipe is. If kg of flour is used, how

much:

:: 2:15:0510::

IGCSE01

cyan magenta yellow black

(^05255075950525507595)
100 100
(^05255075950525507595)
100 100
Y:\HAESE\IGCSE01\IG01_AS\020IGCSE01_AS.CDR Thursday, 11 September 2008 9:38:56 AM PETER
(Page included on the Student CD only)