Claire's school organized a trip to Maldives. At first, the ratio of the number of girls to the number of boys who planned to participate in the trip was 8 : 7. On the day of registration, 25 boys decided to withdraw and 25 more girls decided to join in. In the end, the number of boys who participated became 30% of the total children for the trip. How many children would visit Maldives in the end?

	Girls	Boys	Total
Before	8x2 = 16 u	7x2 = 14 u	15x2 = 30 u
Change	+ 5 u	- 5 u
After	7x3 = 21 u	3x3 = 9 u	10x3 = 30 u

30% = ³⁰₁₀₀ = ³₁₀

Since 25 boys withdrew and another 25 girls joined, the total number of children at first and in the end remains unchanged. Make the total number of children the same. LCM of 15 and 10 is 30.

Number of boys who decided to withdraw
= 14 u - 9 u
= 5 u

5 u = 25

1 u = 25 ÷ 5 = 5

Number of children that would visit Maldives in the end
= 21 u + 9 u
= 30 u
= 30 x 5
= 150

Answer(s): 150