Dylan bought some staplers at $6 each. He later sold them to his customers at $9 each. For customers who bought four staplers were given another stapler for free. The customers bought either one or four staplers. Dylan gave away 120 free staplers and collected a total of $840 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 5 staplers each |
| Number |
1 u |
1 u - 600 |
600 |
| Value |
$6 |
$9 |
$9 |
| Total Value |
6 u |
9 u - $5400 |
$4320 |
Since 120 staplers were given free, there were 120 customers who bought four staplers each.
Number of staplers that each customer would get if they bought four staplers each and got 1 stapler free
= 4 + 1
= 5
Total number of staplers for customers who each bought four staplers
= 5 x 120
= 600
Number of staplers for customers who each bought 1 stapler = 1 u - 600
Total amount collected from customers who bought 1 stapler each
= 9 x (1 u - 600)
= 9 u - 5400
Total amount collected from customers who bought four staplers each
= 120 x 4 x 9
= $4320
Total amount collected from all the customers
= 9 u - 5400 + 4320
= 9 u - 1080
Dylan collected a total of $840 more than what he had paid for.
9 u - 1080 = 6 u + 840
9 u - 6 u = 840 + 1080
3 u = 1920
1 u = 1920 ÷ 3 = 640
Number of customers who bought just one stapler
= 1 u - 600
= 640 - 600
= 40
Answer(s): 40
