The average number of girls in 5A, 5B and 5C is 12. This is 3 more than the average number of boys in the 3 rooms.
29 of the total number of boys are in 5C.
52 of the number of boys in 5B is the same as
59 of the total number of boys in the 3 rooms. What fraction of the total number of girls in the 3 rooms is in 5A if there are 34 pupils in 5A?
| Boys in 5A |
Boys in 5B |
Boys in 5C |
Total boys |
| 7 |
2 |
9 |
| |
2 |
|
9 |
| 5 u |
2 u |
2 u |
9 u |
52 of boys in 5B =
59 of all boys
Boys in 5B : All boys = 2 : 9
Average number of boys
= 12 - 3
= 9
Total number of boys
= 3 x 9
= 27
9 u = 27
1 u = 27 ÷ 9 = 3
Number of boys in Room 5A
= 5 u
= 5 x 3
= 15
Number of girls in Room 5A
= 34 - 15
= 19
Total number of girls
= 3 x 12
= 36
Girls in 5ATotal girls =
1936 Answer(s):
1936 
