There were 4 more girls than boys in the music room. Excluding 10 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 |
4 more |
|
Before |
5 u |
4 u + 10 |
Change |
+ 4 |
|
After |
5 u + 4 |
4 u + 10 |
Number of girls at first was 4 more than the number of boys. If another 4 boys entered the music room at first, the number of girls and boys at first would be the same.
5 u = 4 u + 10 + 4
5 u - 4 u = 10 + 4
1 u = 14
Total number of girls in the end
= 5 u + 4
= 5 x 14 + 4
= 70 + 4
= 74
Total number of pupils in the end
= 5 u + 4 + 4 u + 10
= 9 u + 14
= 9 x 14 + 14
= 140
Fraction of the pupils who were girls in the end
=
74140 =
3770 Answer(s):
3770