Jackson's school organized a trip to Egypt. At first, the ratio of the number of boys to the number of girls who planned to participate in the trip was 7 : 5. On the day of registration, 57 girls decided to withdraw and 57 more boys decided to join in. In the end, the number of girls who participated became 10% of the total children for the trip. How many less girls than boys would visit Egypt in the end?

	Boys	Girls	Total
Before	7x5 = 35 u	5x5 = 25 u	12x5 = 60 u
Change	+ 19 u	- 19 u
After	9x6 = 54 u	1x6 = 6 u	10x6 = 60 u

10% = ¹⁰₁₀₀ = ¹₁₀

Since 57 girls withdrew and another 57 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 12 and 10 is 60.

Number of girls who decided to withdraw
= 25 u - 6 u
= 19 u

19 u = 57

1 u = 57 ÷ 19 = 3

Number of less girls than boys in the end
= 54 u - 6 u
= 48 u
= 48 x 3
= 144

Answer(s): 144