Zeph bought some staplers at $6 each. He later sold them to his customers at $9 each. For customers who bought two staplers were given another stapler for free. The customers bought either one or two staplers. Zeph gave away 160 free staplers and collected a total of $480 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 - 480 |
480 |
| Value |
$6 |
$9 |
$9 |
| Total Value |
6 u |
9 u - $4320 |
$2880 |
Since 160 staplers were given free, there were 160 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 160
= 480
Number of staplers for customers who each bought 1 stapler = 1 u - 480
Total amount collected from customers who bought 1 stapler each
= 9 x (1 u - 480)
= 9 u - 4320
Total amount collected from customers who bought two staplers each
= 160 x 2 x 9
= $2880
Total amount collected from all the customers
= 9 u - 4320 + 2880
= 9 u - 1440
Zeph collected a total of $480 more than what he had paid for.
9 u - 1440 = 6 u + 480
9 u - 6 u = 480 + 1440
3 u = 1920
1 u = 1920 ÷ 3 = 640
Number of customers who bought just one stapler
= 1 u - 480
= 640 - 480
= 160
Answer(s): 160
