There were 10 more boys than girls in the tuck shop. Excluding 7 girls, the number of girls was
34 of the number of boys. When another 4 boys joined, what fraction of the pupils were boys in the end? Give your answer in its simplest form.
|
Boys |
Girls |
Comparing boys and girls at first |
10 more |
|
Before |
4 u |
3 u + 7 |
Change |
+ 4 |
|
After |
4 u + 4 |
3 u + 7 |
Number of boys at first was 10 more than the number of girls. If another 10 girls entered the tuck shop at first, the number of boys and girls at first would be the same.
4 u = 3 u + 7 + 10
4 u - 3 u = 7 + 10
1 u = 17
Total number of boys in the end
= 4 u + 4
= 4 x 17 + 4
= 68 + 4
= 72
Total number of pupils in the end
= 4 u + 4 + 3 u + 7
= 7 u + 11
= 7 x 17 + 11
= 130
Fraction of the pupils who were boys in the end
=
72130 =
3665 Answer(s):
3665