The average number of girls in 6A, 6B and 6C is 17. This is 3 more than the average number of boys in the 3 rooms.
314 of the total number of boys are in 6C.
32 of the number of boys in 6B is the same as
314 of the total number of boys in the 3 rooms. What fraction of the total number of girls in the 3 rooms is in 6A if there are 39 pupils in 6A?
| Boys in 6A |
Boys in 6B |
Boys in 6C |
Total boys |
| 11 |
3 |
14 |
| |
2 |
|
14 |
| 9 u |
2 u |
3 u |
14 u |
32 of boys in 6B =
314 of all boys
Boys in 6B : All boys = 2 : 14
Average number of boys
= 17 - 3
= 14
Total number of boys
= 3 x 14
= 42
14 u = 42
1 u = 42 ÷ 14 = 3
Number of boys in Room 6A
= 9 u
= 9 x 3
= 27
Number of girls in Room 6A
= 39 - 27
= 12
Total number of girls
= 3 x 17
= 51
Girls in 6ATotal girls =
1251 =
417 Answer(s):
417 
