The average number of boys in 2A, 2B and 2C is 18. This is 3 more than the average number of girls in the 3 rooms.
19 of the total number of girls are in 2C.
12 of the number of girls in 2B is the same as
19 of the total number of girls in the 3 rooms. What fraction of the total number of boys in the 3 rooms is in 2A if there are 47 students in 2A?
| Girls in 2A |
Girls in 2B |
Girls in 2C |
Total girls |
| 8 |
1 |
9 |
| |
2 |
|
9 |
| 6 u |
2 u |
1 u |
9 u |
12 of girls in 2B =
19 of all girls
Girls in 2B : All girls = 2 : 9
Average number of girls
= 18 - 3
= 15
Total number of girls
= 3 x 15
= 45
9 u = 45
1 u = 45 ÷ 9 = 5
Number of girls in Room 2A
= 6 u
= 6 x 5
= 30
Number of boys in Room 2A
= 47 - 30
= 17
Total number of boys
= 3 x 18
= 54
Boys in 2ATotal boys =
1754 Answer(s):
1754 
