Julie's school organized a trip to Finland. At first, the ratio of the number of girls to the number of boys who planned to participate in the trip was 7 : 4. 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 25% of the total children for the trip. How many children would visit Finland in the end?

	Girls	Boys	Total
Before	7x4 = 28 u	4x4 = 16 u	11x4 = 44 u
Change	+ 5 u	- 5 u
After	3x11 = 33 u	1x11 = 11 u	4x11 = 44 u

25% = ²⁵₁₀₀ = ¹₄

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 11 and 4 is 44.

Number of boys who decided to withdraw
= 16 u - 11 u
= 5 u

5 u = 25

1 u = 25 ÷ 5 = 5

Number of children that would visit Finland in the end
= 33 u + 11 u
= 44 u
= 44 x 5
= 220

Answer(s): 220