The average number of boys in 4A, 4B and 4C is 17. This is 4 more than the average number of girls in the 3 rooms.
113 of the total number of girls are in 4C.
52 of the number of girls in 4B is the same as
513 of the total number of girls in the 3 rooms. What fraction of the total number of boys in the 3 rooms is in 4A if there are 48 children in 4A?
| Girls in 4A |
Girls in 4B |
Girls in 4C |
Total girls |
| 12 |
1 |
13 |
| |
2 |
|
13 |
| 10 u |
2 u |
1 u |
13 u |
52 of girls in 4B =
513 of all girls
Girls in 4B : All girls = 2 : 13
Average number of girls
= 17 - 4
= 13
Total number of girls
= 3 x 13
= 39
13 u = 39
1 u = 39 ÷ 13 = 3
Number of girls in Room 4A
= 10 u
= 10 x 3
= 30
Number of boys in Room 4A
= 48 - 30
= 18
Total number of boys
= 3 x 17
= 51
Boys in 4ATotal boys =
1851 =
617 Answer(s):
617 
