Justin bought some markers at $3 each. He later sold them to his customers at $7 each. For customers who bought four markers were given another marker for free. The customers bought either one or four markers. Justin gave away 110 free markers and collected a total of $2350 more than what he had paid for. How many customers bought just one marker each?
|
Markers sold |
Markers given to customers who got 1 marker each |
Markers given to customers who got 5 markers each |
Number |
1 u |
1 u - 550 |
550 |
Value |
$3 |
$7 |
$7 |
Total Value |
3 u |
7 u - $3850 |
$3080 |
Since 110 markers were given free, there were 110 customers who bought four markers each.
Number of markers that each customer would get if they bought four markers each and got 1 marker free
= 4 + 1
= 5
Total number of markers for customers who each bought four markers
= 5 x 110
= 550
Number of markers for customers who each bought 1 marker = 1 u - 550
Total amount collected from customers who bought 1 marker each
= 7 x (1 u - 550)
= 7 u - 3850
Total amount collected from customers who bought four markers each
= 110 x 4 x 7
= $3080
Total amount collected from all the customers
= 7 u - 3850 + 3080
= 7 u - 770
Justin collected a total of $2350 more than what he had paid for.
7 u - 770 = 3 u + 2350
7 u - 3 u = 2350 + 770
4 u = 3120
1 u = 3120 ÷ 4 = 780
Number of customers who bought just one marker
= 1 u - 550
= 780 - 550
= 230
Answer(s): 230