The average number of girls in 5A, 5B and 5C is 17. This is 3 more than the average number of boys in the 3 rooms.
27 of the total number of boys are in 5C.
52 of the number of boys in 5B 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 5A if there are 38 children in 5A?
Boys in 5A |
Boys in 5B |
Boys in 5C |
Total boys |
5 |
2 |
7 |
|
2 |
|
7 |
3 u |
2 u |
2 u |
7 u |
52 of boys in 5B =
57 of all boys
Boys in 5B : 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 5A
= 3 u
= 3 x 6
= 18
Number of girls in Room 5A
= 38 - 18
= 20
Total number of girls
= 3 x 17
= 51
Girls in 5ATotal girls =
2051 Answer(s):
2051