During a donation drive, $2920 was collected by 80 pupils. Each boy donated $40 and each girl donated $30. 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 40 = $3200 |
0 |
0
|
$3200 |
79
|
79 x 40 = $3160 |
1 |
1 x 30 = $30 |
$3190 |
52
|
52 x 40 = $2080 |
28
|
28 x 30 = $840 |
$2920
|
Total amount collected if all the donations were made by boys
= 80 x 40
= $3200
Big difference in the total amounts made between the boys and the girls
= 3200 - 2920
= $280
Small difference in the amount made between one boy and one girl
= 40 - 30
= $10
Number of girls
= 280 ÷ 10
= 28
Number of boys
= 80 - 28
= 52
Answer(s): 52