The average number of boys in 6A, 6B and 6C is 15. This is 4 more than the average number of girls in the 3 rooms.
111 of the total number of girls are in 6C.
52 of the number of girls in 6B is the same as
511 of the total number of girls in the 3 rooms. What fraction of the total number of boys in the 3 rooms is in 6A if there are 34 pupils in 6A?
| Girls in 6A |
Girls in 6B |
Girls in 6C |
Total girls |
| 10 |
1 |
11 |
| |
2 |
|
11 |
| 8 u |
2 u |
1 u |
11 u |
52 of girls in 6B =
511 of all girls
Girls in 6B : All girls = 2 : 11
Average number of girls
= 15 - 4
= 11
Total number of girls
= 3 x 11
= 33
11 u = 33
1 u = 33 ÷ 11 = 3
Number of girls in Room 6A
= 8 u
= 8 x 3
= 24
Number of boys in Room 6A
= 34 - 24
= 10
Total number of boys
= 3 x 15
= 45
Boys in 6ATotal boys =
1045 =
29 Answer(s):
29 
