There were 8 more girls than boys in the computer lab. Excluding 6 boys, the number of boys was
45 of the number of girls. When another 12 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 |
8 more |
|
Before |
5 u |
4 u + 6 |
Change |
+ 12 |
|
After |
5 u + 12 |
4 u + 6 |
Number of girls at first was 8 more than the number of boys. If another 8 boys entered the computer lab at first, the number of girls and boys at first would be the same.
5 u = 4 u + 6 + 8
5 u - 4 u = 6 + 8
1 u = 14
Total number of girls in the end
= 5 u + 12
= 5 x 14 + 12
= 70 + 12
= 82
Total number of pupils in the end
= 5 u + 12 + 4 u + 6
= 9 u + 18
= 9 x 14 + 18
= 144
Fraction of the pupils who were girls in the end
=
82144 =
4172 Answer(s):
4172