There were 121 children enrolled in the Marion Dancing School in 2022. ⁴₁₁ of the children were boys. Additional children joined the dancing school in 2023. For every 4 boys who joined the dancing school, 3 girls joined the dancing school. If there was an equal number of girls and boys in 2023, how many girls joined the school in that year?

	Boys	Girls
Before	44	77
Change	+ 4 u	+ 3 u
After	44 + 4 u	77 + 3 u

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

Number of boys at first
= ⁴₁₁ x 121
= 44

Number of girls at first
= ⁷₁₁ x 121
= 77

Boys who joined : Girls who joined
4 : 3

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

44 + 4 u = 77 + 3 u
4 u - 3 u = 77 - 44

1 u = 33

Number of girls who joined the school in that year
= 3 u
= 3 x 33
= 99

Answer(s): 99