At a school event there were 96 girls. the ratio of number of girls to the number of boys was 4:5. after some time some boys arrived and the ratio became 2:3. how many boys arrived?

Given:

number of girls: 96

ratio girls to boys : 4:5

find the number of boys:

96 / 4 = 24 * 5 = 120 number of boys

4:5 ⇒ 96 : 120

Additional boys arrived making the ration 2:3

96/2 = 48 * 3 = 144 number of boys

144 - 120 = 24 additional boys arrived.

2:3 ⇒ 96:144