42 students in a class sold an average of 21 stickers for charity. There were 6 more boys than girls in the class. The average number of stickers sold by the boys was 18. Find the average number of stickers sold by the girls.
| |
Girls |
Boys |
Total |
| Number |
1 u |
1 u + 6 |
42 |
| Value |
? |
18 |
21 |
| Total value |
450 |
432 |
882 |
Total number of stickers sold
= 42 x 21
= 882
Number of girls = 1 u
Number of boys = 1 u + 6
1 u + 1 u + 6 = 42
2 u + 6 = 42
2 u = 42 - 6
2 u = 36
1 u = 36 ÷ 2 = 18
Number of boys in class
= 1 u + 6
= 18 + 6
= 24
Number of stickers sold by boys
= 24 x 18
= 432
Number of stickers sold by girls
= 882 - 432
= 450
Average number of stickers sold by girls
= 450 ÷ 18
= 25
Answer(s): 25
