Page 113 - ICSE Math 6

Example 9: Compare the following ratios.
(a) 5 : 9 and 6 : 11 (b) 3 : 5 and 13 : 15 (c) 30 : 65 and 6 : 13
5 6 3 13
Solution: (a) 5 : 9 = and 6 : 11 = (b) 3 : 5 = and 13 : 15 =
9 11 5 15
5 × 11 = 55 and 9 × 6 = 54 3 × 15 = 45 and 5 × 13 = 65
5 6 3 13
55 > 54 ⇒ > 45 < 65 ⇒ <
9 11 5 15
\ 5 : 9 > 6 : 11 \ 3 : 5 < 13 : 15
30 6
(c) 30 : 65 = and 6 : 13 =
65 13
30 × 13 = 390 and 65 × 6 = 390
30 6
390 = 390 ⇒ 65 = 13

\ 30 : 65 = 6 : 13

EXERCISE 8.1

1. Fill in the blanks.
(a) For the ratio 3 : 7, the antecedent is __________ and the consequent is __________.
(b) For the ratio 13 : 21, the first term is __________ and the second term is __________.

(c) If the first term is 17 and the second term is 23, then the ratio is given by __________.
(d) If the antecedent is 12 and the consequent is 97 then the ratio is __________.
2. Find the ratio between the following.

(a) 1 kg and 900 g (b) 90 paise and ` 3.30
(c) 1 m 30 cm and 40 cm (d) 2 h 20 min and 8 min
3. Write the given ratios in their simplest forms.

3 2 7
(a) 1,200 : 500 (b) 48 : 32 (c) 1 : (d) :
5 7 6

4. In a committee of 440 members, 110 members are women and the rest are all men. Find the ratio
between the number of women and men in the commiittee.
5. Tarun is twice as old as Tia. Write the ratio of Tarun’s age to Tia’s age and Tia’s age to Tarun’s
age.
6. A ratio in its lowest terms is 3 : 5.

(a) Find its antecedent if its consequent is 40.
(b) Find its consequent if its antecedent is 27.
7. The ratio of the ages of a son and his father is 4 : 9. If the father is 54 years old, find the age of
the son.

8. Divide 75 in the ratio 2 : 3.
9. Divide ` 2,000 between two persons in the ratio 9 : 11.
10. The sides of a triangle are in the ratio 4 : 7 : 9. If the perimeter of the triangle is 400 cm, then
find the sides of the triangle.

97