Owen bought some pencils at $5 each. He later sold them to his customers at $7 each. For customers who bought two pencils were given another pencil for free. The customers bought either one or two pencils. Owen gave away 120 free pencils and collected a total of $480 more than what he had paid for. How many customers bought just one pencil each?
|
Pencils sold |
Pencils given to customers who got 1 pencil each |
Pencils given to customers who got 3 pencils each |
Number |
1 u |
1 u - 360 |
360 |
Value |
$5 |
$7 |
$7 |
Total Value |
5 u |
7 u - $2520 |
$1680 |
Since 120 pencils were given free, there were 120 customers who bought two pencils each.
Number of pencils that each customer would get if they bought two pencils each and got 1 pencil free
= 2 + 1
= 3
Total number of pencils for customers who each bought two pencils
= 3 x 120
= 360
Number of pencils for customers who each bought 1 pencil = 1 u - 360
Total amount collected from customers who bought 1 pencil each
= 7 x (1 u - 360)
= 7 u - 2520
Total amount collected from customers who bought two pencils each
= 120 x 2 x 7
= $1680
Total amount collected from all the customers
= 7 u - 2520 + 1680
= 7 u - 840
Owen collected a total of $480 more than what he had paid for.
7 u - 840 = 5 u + 480
7 u - 5 u = 480 + 840
2 u = 1320
1 u = 1320 ÷ 2 = 660
Number of customers who bought just one pencil
= 1 u - 360
= 660 - 360
= 300
Answer(s): 300