There were 11 more girls than boys in the classroom. Excluding 10 boys, the number of boys was
23 of the number of girls. When another 7 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 |
11 more |
|
Before |
3 u |
2 u + 10 |
Change |
+ 7 |
|
After |
3 u + 7 |
2 u + 10 |
Number of girls at first was 11 more than the number of boys. If another 11 boys entered the classroom at first, the number of girls and boys at first would be the same.
3 u = 2 u + 10 + 11
3 u - 2 u = 10 + 11
1 u = 21
Total number of girls in the end
= 3 u + 7
= 3 x 21 + 7
= 63 + 7
= 70
Total number of students in the end
= 3 u + 7 + 2 u + 10
= 5 u + 17
= 5 x 21 + 17
= 122
Fraction of the students who were girls in the end
=
70122 =
3561 Answer(s):
3561