In a school there were 1554 students and the ratio of the

In a school there were 1554 students and the ratio of the number of the boys and girls was 4 : 3. After a few days, 30 girls joined the school but a few boys left; as a result the ratio of the boys and girls became 7 : 6. The number of boys who left the school is

In the school,

Boys ⇒	4	× 1554 = 888
	7

Girls ⇒	3	× 1554 = 666
	7

After 30 days,
Girls = 666 + 30 = 696
If x boys leave the school, then,
According to the question,

888 − x	=	7
696	=	6

⇒	888 − x	= 7
	116

⇒ 888 – x = 116 × 7 = 812
⇒ x = 888 – 812 = 76