Raeann's school organized a trip to Pakistan. At first, the ratio of the number of boys to the number of girls who planned to participate in the trip was 8 : 7. On the day of registration, 10 girls decided to withdraw and 10 more boys decided to join in. In the end, the number of girls who participated became 30% of the total children for the trip. How many more boys than girls would visit Pakistan in the end?

	Boys	Girls	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 10 girls withdrew and another 10 boys 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 girls who decided to withdraw
= 14 u - 9 u
= 5 u

5 u = 10

1 u = 10 ÷ 5 = 2

Number of more boys than girls in the end
= 21 u - 9 u
= 12 u
= 12 x 2
= 24

Answer(s): 24