The average number of girls in 3A, 3B and 3C is 17. This is 3 more than the average number of boys in the 3 rooms.
37 of the total number of boys are in 3C.
32 of the number of boys in 3B is the same as
37 of the total number of boys in the 3 rooms. What fraction of the total number of girls in the 3 rooms is in 3A if there are 24 students in 3A?
| Boys in 3A |
Boys in 3B |
Boys in 3C |
Total boys |
| 4 |
3 |
7 |
| |
2 |
|
7 |
| 2 u |
2 u |
3 u |
7 u |
32 of boys in 3B =
37 of all boys
Boys in 3B : All boys = 2 : 7
Average number of boys
= 17 - 3
= 14
Total number of boys
= 3 x 14
= 42
7 u = 42
1 u = 42 ÷ 7 = 6
Number of boys in Room 3A
= 2 u
= 2 x 6
= 12
Number of girls in Room 3A
= 24 - 12
= 12
Total number of girls
= 3 x 17
= 51
Girls in 3ATotal girls =
1251 =
417 Answer(s):
417 
