During a donation drive, $3730 was collected by 80 students. Each girl donated $50 and each boy donated $40. 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 50 =
$4000 |
0 |
0
|
$4000 |
79
|
79 x 50 =
$3950 |
1 |
1 x 40 =
$40 |
$3990 |
53
|
53 x 50 =
$2650 |
27
|
27 x 40 =
$1080 |
$3730
|
Total amount collected if all the donations were made by girls
= 80 x 50
= $4000
Big difference in the total amounts made between the girls and the boys
= 4000 - 3730
= $270
Small difference in the amount made between one girl and one boy
= 50 - 40
= $10
Number of boys
= 270 ÷ 10
= 27
Number of girls
= 80 - 27
= 53
Answer(s): 53
