Lilian's school organized a trip to Maldives. At first, the ratio of the number of boys to the number of girls who planned to participate in the trip was 10 : 9. On the day of registration, 51 girls decided to withdraw and 51 more boys decided to join in. In the end, the number of girls who participated became 25% of the total children for the trip. How many more boys than girls would visit Maldives in the end?

	Boys	Girls	Total
Before	10x4 = 40 u	9x4 = 36 u	19x4 = 76 u
Change	+ 17 u	- 17 u
After	3x19 = 57 u	1x19 = 19 u	4x19 = 76 u

25% = ²⁵₁₀₀ = ¹₄

Since 51 girls withdrew and another 51 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 19 and 4 is 76.

Number of girls who decided to withdraw
= 36 u - 19 u
= 17 u

17 u = 51

1 u = 51 ÷ 17 = 3

Number of more boys than girls in the end
= 57 u - 19 u
= 38 u
= 38 x 3
= 114

Answer(s): 114