There were 9 more girls than boys in the gymnasium. Excluding 11 boys, the number of boys was
45 of the number of girls. When another 4 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 |
9 more |
|
Before |
5 u |
4 u + 11 |
Change |
+ 4 |
|
After |
5 u + 4 |
4 u + 11 |
Number of girls at first was 9 more than the number of boys. If another 9 boys entered the gymnasium at first, the number of girls and boys at first would be the same.
5 u = 4 u + 11 + 9
5 u - 4 u = 11 + 9
1 u = 20
Total number of girls in the end
= 5 u + 4
= 5 x 20 + 4
= 100 + 4
= 104
Total number of pupils in the end
= 5 u + 4 + 4 u + 11
= 9 u + 15
= 9 x 20 + 15
= 195
Fraction of the pupils who were girls in the end
=
104195 =
815 Answer(s):
815