22 pupils in a class sold an average of 21 stickers for charity. There were 6 more girls than boys in the class. The average number of stickers sold by the girls was 17. Find the average number of stickers sold by the boys.
| |
Boys |
Girls |
Total |
| Number |
1 u |
1 u + 6 |
22 |
| Value |
? |
17 |
21 |
| Total value |
224 |
238 |
462 |
Total number of stickers sold
= 22 x 21
= 462
Number of boys = 1 u
Number of girls = 1 u + 6
1 u + 1 u + 6 = 22
2 u + 6 = 22
2 u = 22 - 6
2 u = 16
1 u = 16 ÷ 2 = 8
Number of girls in class
= 1 u + 6
= 8 + 6
= 14
Number of stickers sold by girls
= 14 x 17
= 238
Number of stickers sold by boys
= 462 - 238
= 224
Average number of stickers sold by boys
= 224 ÷ 8
= 28
Answer(s): 28
