There were 126 children enrolled in the Xylia Dancing School in 2021. ³₇ of the children were girls. Additional children joined the dancing school in 2022. For every 3 girls who joined the dancing school, 2 boys joined the dancing school. If there was an equal number of boys and girls in 2022, how many boys joined the school in that year?

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

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

Number of girls at first
= ³₇ x 126
= 54

Number of boys at first
= ⁴₇ x 126
= 72

Girls who joined : Boys who joined
3 : 2

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

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

1 u = 18

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

Answer(s): 36