Question

The ratio between the number of boys and girls in a school is 5 : 7. In the next session, the number of boys are increased by 30% and the number of girls increased by 20%. Then what will be the new ratio of boys and girls in the school?
1. 70 : 84
2. 65 : 80
3. 72 : 82
4. 62 : 80
5. 65 : 84

Answer 1

Correct Answer - Option 5 : 65 : 84

Given:

Ratio of number of boys and girls = 5 : 7

In the next session,

Boys increased by 30% &

Girls increased by 20%

Calculation:

Let the number of boys and girls be 5x and 7x respectively.

In the next session,

Increased number of boys = 5x × 130 / 100

⇒ Increased number of boys = 13x / 2

Increased number of girls = 7x × 120 / 100

⇒ Increased number of girls = 42x / 5

∴ Ratio of Increased number of boys to increased number of girls

⇒ (13x / 2) / (42x / 5)

⇒ 65 : 84