Charlie bought some staplers at $3 each. He later sold them to his customers at $5 each. For customers who bought three staplers were given another stapler for free. The customers bought either one or three staplers. Charlie gave away 100 free staplers and collected a total of $560 more than what he had paid for. How many customers bought just one stapler each?
| |
Staplers
sold |
Staplers given to customers who got 1 stapler each |
Staplers given to customers who got 4 staplers each |
| Number |
1 u |
1 u - 400 |
400 |
| Value |
$3 |
$5 |
$5 |
| Total Value |
3 u |
5 u - $2000 |
$1500 |
Since 100 staplers were given free, there were 100 customers who bought three staplers each.
Number of staplers that each customer would get if they bought three staplers each and got 1 stapler free
= 3 + 1
= 4
Total number of staplers for customers who each bought three staplers
= 4 x 100
= 400
Number of staplers for customers who each bought 1 stapler = 1 u - 400
Total amount collected from customers who bought 1 stapler each
= 5 x (1 u - 400)
= 5 u - 2000
Total amount collected from customers who bought three staplers each
= 100 x 3 x 5
= $1500
Total amount collected from all the customers
= 5 u - 2000 + 1500
= 5 u - 500
Charlie collected a total of $560 more than what he had paid for.
5 u - 500 = 3 u + 560
5 u - 3 u = 560 + 500
2 u = 1060
1 u = 1060 ÷ 2 = 530
Number of customers who bought just one stapler
= 1 u - 400
= 530 - 400
= 130
Answer(s): 130
