The average number of girls in 4A, 4B and 4C is 11. This is 4 more than the average number of boys in the 3 rooms.
37 of the total number of boys are in 4C.
52 of the number of boys in 4B is the same as
57 of the total number of boys in the 3 rooms. What fraction of the total number of girls in the 3 rooms is in 4A if there are 20 children in 4A?
| Boys in 4A |
Boys in 4B |
Boys in 4C |
Total boys |
| 4 |
3 |
7 |
| |
2 |
|
7 |
| 2 u |
2 u |
3 u |
7 u |
52 of boys in 4B =
57 of all boys
Boys in 4B : All boys = 2 : 7
Average number of boys
= 11 - 4
= 7
Total number of boys
= 3 x 7
= 21
7 u = 21
1 u = 21 ÷ 7 = 3
Number of boys in Room 4A
= 2 u
= 2 x 3
= 6
Number of girls in Room 4A
= 20 - 6
= 14
Total number of girls
= 3 x 11
= 33
Girls in 4ATotal girls =
1433 Answer(s):
1433 
