During a donation drive, $2110 was collected by 50 pupils. Each boy donated $50 and each girl donated $40. 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 40 = $40 |
$2490 |
11
|
11 x 50 = $550 |
39
|
39 x 40 = $1560 |
$2110
|
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 - 2110
= $390
Small difference in the amount made between one boy and one girl
= 50 - 40
= $10
Number of girls
= 390 ÷ 10
= 39
Number of boys
= 50 - 39
= 11
Answer(s): 11