Tommy bought some staplers at $6 each. He later sold them to his customers at $10 each. For customers who bought two staplers were given another stapler for free. The customers bought either one or two staplers. Tommy gave away 130 free staplers and collected a total of $1140 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 3 staplers each |
| Number |
1 u |
1 u - 390 |
390 |
| Value |
$6 |
$10 |
$10 |
| Total Value |
6 u |
10 u - $3900 |
$2600 |
Since 130 staplers were given free, there were 130 customers who bought two staplers each.
Number of staplers that each customer would get if they bought two staplers each and got 1 stapler free
= 2 + 1
= 3
Total number of staplers for customers who each bought two staplers
= 3 x 130
= 390
Number of staplers for customers who each bought 1 stapler = 1 u - 390
Total amount collected from customers who bought 1 stapler each
= 10 x (1 u - 390)
= 10 u - 3900
Total amount collected from customers who bought two staplers each
= 130 x 2 x 10
= $2600
Total amount collected from all the customers
= 10 u - 3900 + 2600
= 10 u - 1300
Tommy collected a total of $1140 more than what he had paid for.
10 u - 1300 = 6 u + 1140
10 u - 6 u = 1140 + 1300
4 u = 2440
1 u = 2440 ÷ 4 = 610
Number of customers who bought just one stapler
= 1 u - 390
= 610 - 390
= 220
Answer(s): 220
