In a school 3/5 pupils are boys. One day 1/5 of the girls were absent when 80 girls were present. How many pupils are in the school?

Question

Answer that i expect is 250.

Answer 1

3/5 are boys and 2/5 are girls

So of the N students, (2/5)N are girls.

1/5 of the girls were absent, which means 4/5 of the girls, or 80 of them, were present.

(4/5)(2/5)N = 80 <--- 4/5 of the girls were present, or (4/5) of (2/5) of the entire study population

(8/25)N = 80

N = 80*25/8 = 250

there are 250 students altogether

3/5 of them is 150 boys

2/5 of them is 100 girls

1/5 of the girls , or 20 of them were absent, which

means 4/5 of the girls , or 80 of them , were present.

there are 250 students altogether