There were 4 more girls than boys in the computer lab. Excluding 3 boys, the number of boys was
34 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 |
4 more |
|
Before |
4 u |
3 u + 3 |
Change |
+ 5 |
|
After |
4 u + 5 |
3 u + 3 |
Number of girls at first was 4 more than the number of boys. If another 4 boys entered the computer lab at first, the number of girls and boys at first would be the same.
4 u = 3 u + 3 + 4
4 u - 3 u = 3 + 4
1 u = 7
Total number of girls in the end
= 4 u + 5
= 4 x 7 + 5
= 28 + 5
= 33
Total number of pupils in the end
= 4 u + 5 + 3 u + 3
= 7 u + 8
= 7 x 7 + 8
= 57
Fraction of the pupils who were girls in the end
=
3357 =
1119 Answer(s):
1119