There were 154 children enrolled in the Gabby Dancing School in 2016. ⁴₁₁ of the children were girls. Additional children joined the dancing school in 2017. For every 4 girls who joined the dancing school, 3 boys joined the dancing school. If there was an equal number of boys and girls in 2017, how many boys joined the school in that year?

	Girls	Boys
Before	56	98
Change	+ 4 u	+ 3 u
After	56 + 4 u	98 + 3 u

Fraction of children who are boys
= 1 - ⁴₁₁
= ⁷₁₁

Number of girls at first
= ⁴₁₁ x 154
= 56

Number of boys at first
= ⁷₁₁ x 154
= 98

Girls who joined : Boys who joined
4 : 3

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

56 + 4 u = 98 + 3 u
4 u - 3 u = 98 - 56

1 u = 42

Number of boys who joined the school in that year
= 3 u
= 3 x 42
= 126

Answer(s): 126