During a donation drive, $3010 was collected by 80 pupils. Each boy donated $50 and each girl donated $20. How many boys were there?
Number of boys |
Amount collected by boys |
Number of girls |
Amount collected by girls |
Total amount collected |
80
|
80 x 50 = $4000 |
0 |
0
|
$4000 |
79
|
79 x 50 = $3950 |
1 |
1 x 20 = $20 |
$3970 |
47
|
47 x 50 = $2350 |
33
|
33 x 20 = $660 |
$3010
|
Total amount collected if all the donations were made by boys
= 80 x 50
= $4000
Big difference in the total amounts made between the boys and the girls
= 4000 - 3010
= $990
Small difference in the amount made between one boy and one girl
= 50 - 20
= $30
Number of girls
= 990 ÷ 30
= 33
Number of boys
= 80 - 33
= 47
Answer(s): 47