The average number of boys in 6A, 6B and 6C is 20. This is 4 more than the average number of girls in the 3 rooms.
38 of the total number of girls are in 6C.
52 of the number of girls in 6B is the same as
58 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 31 students in 6A?
| Girls in 6A |
Girls in 6B |
Girls in 6C |
Total girls |
| 5 |
3 |
8 |
| |
2 |
|
8 |
| 3 u |
2 u |
3 u |
8 u |
52 of girls in 6B =
58 of all girls
Girls in 6B : All girls = 2 : 8
Average number of girls
= 20 - 4
= 16
Total number of girls
= 3 x 16
= 48
8 u = 48
1 u = 48 ÷ 8 = 6
Number of girls in Room 6A
= 3 u
= 3 x 6
= 18
Number of boys in Room 6A
= 31 - 18
= 13
Total number of boys
= 3 x 20
= 60
Boys in 6ATotal boys =
1360 Answer(s):
1360 
