There were 9 more girls than boys in the school hall. Excluding 6 boys, the number of boys was
45 of the number of girls. When another 5 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 + 6 |
Change |
+ 5 |
|
After |
5 u + 5 |
4 u + 6 |
Number of girls at first was 9 more than the number of boys. If another 9 boys entered the school hall at first, the number of girls and boys at first would be the same.
5 u = 4 u + 6 + 9
5 u - 4 u = 6 + 9
1 u = 15
Total number of girls in the end
= 5 u + 5
= 5 x 15 + 5
= 75 + 5
= 80
Total number of pupils in the end
= 5 u + 5 + 4 u + 6
= 9 u + 11
= 9 x 15 + 11
= 146
Fraction of the pupils who were girls in the end
=
80146 =
4073 Answer(s):
4073