There were 9 more boys than girls in the computer lab. Excluding 11 girls, the number of girls was
23 of the number of boys. When another 8 boys joined, what fraction of the students were boys in the end? Give your answer in its simplest form.
|
Boys |
Girls |
Comparing boys and girls at first |
9 more |
|
Before |
3 u |
2 u + 11 |
Change |
+ 8 |
|
After |
3 u + 8 |
2 u + 11 |
Number of boys at first was 9 more than the number of girls. If another 9 girls entered the computer lab at first, the number of boys and girls at first would be the same.
3 u = 2 u + 11 + 9
3 u - 2 u = 11 + 9
1 u = 20
Total number of boys in the end
= 3 u + 8
= 3 x 20 + 8
= 60 + 8
= 68
Total number of students in the end
= 3 u + 8 + 2 u + 11
= 5 u + 19
= 5 x 20 + 19
= 119
Fraction of the students who were boys in the end
=
68119 =
47 Answer(s):
47