There were 126 children enrolled in the Jade Acting School in 2015. ³₇ of the children were boys. Additional children joined the acting school in 2016. For every 3 boys who joined the acting school, 2 girls joined the acting school. If there was an equal number of girls and boys in 2016, how many girls joined the school in that year?

	Boys	Girls
Before	54	72
Change	+ 3 u	+ 2 u
After	54 + 3 u	72 + 2 u

Fraction of children who are girls
= 1 - ³₇
= ⁴₇

Number of boys at first
= ³₇ x 126
= 54

Number of girls at first
= ⁴₇ x 126
= 72

Boys who joined : Girls who joined
3 : 2

The number of girls and boys in the end is the same.

54 + 3 u = 72 + 2 u
3 u - 2 u = 72 - 54

1 u = 18

Number of girls who joined the school in that year
= 2 u
= 2 x 18
= 36

Answer(s): 36