During a donation drive, $2840 was collected by 80 pupils. Each girl donated $40 and each boy donated $30. How many girls were there?
Number of
girls |
Amount collected
by girls |
Number of
boys |
Amount collected
by boys |
Total amount
collected |
80
|
80 x 40 =
$3200 |
0 |
0
|
$3200 |
79
|
79 x 40 =
$3160 |
1 |
1 x 30 =
$30 |
$3190 |
44
|
44 x 40 =
$1760 |
36
|
36 x 30 =
$1080 |
$2840
|
Total amount collected if all the donations were made by girls
= 80 x 40
= $3200
Big difference in the total amounts made between the girls and the boys
= 3200 - 2840
= $360
Small difference in the amount made between one girl and one boy
= 40 - 30
= $10
Number of boys
= 360 ÷ 10
= 36
Number of girls
= 80 - 36
= 44
Answer(s): 44
