In a college, the ratio of boys to girls is 7 to 8. If the number of boys increases by 20% and the number of girls increases by 10%, what will be the new ratio of boys to girls?

Explanation

Let the initial number of boys be 7x and girls be 8x. After the increase, boys become 7x × 1.20 = 8.4x, and girls become 8x × 1.10 = 8.8x. The new ratio is 8.4x : 8.8x, which simplifies to 21 : 22.