Bobby bought some staplers at $3 each. He later sold them to his customers at $7 each. For customers who bought two staplers were given another stapler for free. The customers bought either one or two staplers. Bobby gave away 210 free staplers and collected a total of $1490 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 - 630 |
630 |
| Value |
$3 |
$7 |
$7 |
| Total Value |
3 u |
7 u - $4410 |
$2940 |
Since 210 staplers were given free, there were 210 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 210
= 630
Number of staplers for customers who each bought 1 stapler = 1 u - 630
Total amount collected from customers who bought 1 stapler each
= 7 x (1 u - 630)
= 7 u - 4410
Total amount collected from customers who bought two staplers each
= 210 x 2 x 7
= $2940
Total amount collected from all the customers
= 7 u - 4410 + 2940
= 7 u - 1470
Bobby collected a total of $1490 more than what he had paid for.
7 u - 1470 = 3 u + 1490
7 u - 3 u = 1490 + 1470
4 u = 2960
1 u = 2960 ÷ 4 = 740
Number of customers who bought just one stapler
= 1 u - 630
= 740 - 630
= 110
Answer(s): 110
