There were 3 more girls than boys in the classroom. Excluding 12 boys, the number of boys was
45 of the number of girls. When another 3 girls joined, what fraction of the students were girls in the end? Give your answer in its simplest form.
|
Girls |
Boys |
Comparing girls and boys at first |
3 more |
|
Before |
5 u |
4 u + 12 |
Change |
+ 3 |
|
After |
5 u + 3 |
4 u + 12 |
Number of girls at first was 3 more than the number of boys. If another 3 boys entered the classroom at first, the number of girls and boys at first would be the same.
5 u = 4 u + 12 + 3
5 u - 4 u = 12 + 3
1 u = 15
Total number of girls in the end
= 5 u + 3
= 5 x 15 + 3
= 75 + 3
= 78
Total number of students in the end
= 5 u + 3 + 4 u + 12
= 9 u + 15
= 9 x 15 + 15
= 150
Fraction of the students who were girls in the end
=
78150 =
1325 Answer(s):
1325