39 children in a class sold an average of 18 cartoon figurines for charity. There were 9 more girls than boys in the class. The average number of cartoon figurines sold by the girls was 13. Find the average number of cartoon figurines sold by the boys.
| |
Boys |
Girls |
Total |
| Number |
1 u |
1 u + 9 |
39 |
| Value |
? |
13 |
18 |
| Total value |
390 |
312 |
702 |
Total number of cartoon figurines sold
= 39 x 18
= 702
Number of boys = 1 u
Number of girls = 1 u + 9
1 u + 1 u + 9 = 39
2 u + 9 = 39
2 u = 39 - 9
2 u = 30
1 u = 30 ÷ 2 = 15
Number of girls in class
= 1 u + 9
= 15 + 9
= 24
Number of cartoon figurines sold by girls
= 24 x 13
= 312
Number of cartoon figurines sold by boys
= 702 - 312
= 390
Average number of cartoon figurines sold by boys
= 390 ÷ 15
= 26
Answer(s): 26
