There were 10 more girls than boys in the school hall. Excluding 9 boys, the number of boys was
45 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 |
10 more |
|
Before |
5 u |
4 u + 9 |
Change |
+ 7 |
|
After |
5 u + 7 |
4 u + 9 |
Number of girls at first was 10 more than the number of boys. If another 10 boys entered the school hall at first, the number of girls and boys at first would be the same.
5 u = 4 u + 9 + 10
5 u - 4 u = 9 + 10
1 u = 19
Total number of girls in the end
= 5 u + 7
= 5 x 19 + 7
= 95 + 7
= 102
Total number of students in the end
= 5 u + 7 + 4 u + 9
= 9 u + 16
= 9 x 19 + 16
= 187
Fraction of the students who were girls in the end
=
102187 =
611 Answer(s):
611