There were 198 children enrolled in the Anna Cooking School in 2017. ⁴₁₁ of the children were boys. Additional children joined the cooking school in 2018. For every 4 boys who joined the cooking school, 3 girls joined the cooking school. If there was an equal number of girls and boys in 2018, how many girls joined the school in that year?

	Boys	Girls
Before	72	126
Change	+ 4 u	+ 3 u
After	72 + 4 u	126 + 3 u

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

Number of boys at first
= ⁴₁₁ x 198
= 72

Number of girls at first
= ⁷₁₁ x 198
= 126

Boys who joined : Girls who joined
4 : 3

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

72 + 4 u = 126 + 3 u
4 u - 3 u = 126 - 72

1 u = 54

Number of girls who joined the school in that year
= 3 u
= 3 x 54
= 162

Answer(s): 162