There were 3 more girls than boys in the computer lab. Excluding 9 boys, the number of boys was ²₃ of the number of girls. When another 8 girls joined, what fraction of the pupils were girls in the end? Give your answer in its simplest form.

	Girls	Boys
Comparing girls  and boys at first	3 more
Before	3 u	2 u + 9
Change	+ 8
After	3 u + 8	2 u + 9

Number of girls at first was 3 more than the number of boys. If another 3 boys entered the computer lab at first, the number of girls and boys at first would be the same.

3 u = 2 u + 9 + 3 
3 u - 2 u = 9 + 3

1 u = 12

Total number of girls in the end
= 3 u + 8
= 3 x 12 + 8
= 36 + 8
= 44

Total number of pupils in the end
= 3 u + 8 + 2 u + 9
= 5 u + 17
= 5 x 12 + 17
= 77

Fraction of the pupils who were girls in the end
= ⁴⁴₇₇
= ⁴₇

Answer(s): ⁴₇