During a donation drive, $1820 was collected by 50 pupils. Each boy donated $50 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 |
50
|
50 x 50 = $2500 |
0 |
0
|
$2500 |
49
|
49 x 50 = $2450 |
1 |
1 x 30 = $30 |
$2480 |
16
|
16 x 50 = $800 |
34
|
34 x 30 = $1020 |
$1820
|
Total amount collected if all the donations were made by boys
= 50 x 50
= $2500
Big difference in the total amounts made between the boys and the girls
= 2500 - 1820
= $680
Small difference in the amount made between one boy and one girl
= 50 - 30
= $20
Number of girls
= 680 ÷ 20
= 34
Number of boys
= 50 - 34
= 16
Answer(s): 16