The park tickets are priced at $21 and $17.  The number of $21-dollar tickets available is  1¹₅ that of the number of $17-dollar tickets. 3 out of 5 of the $21-dollar tickets and all the $17-dollar tickets were sold. The ticket sales amounted to $7227. How much more would have been collected if all the tickets were sold?

	$21	$17
Comparing $21 and $17 tickets at first	6x5 = 30 u	5x5 = 25 u
Before	5x6 = 30 u
Change	- 3x6 = - 18 u	- 25 u
After	2x6 = 12 u	0 u

The number of 21 tickets at first is repeated.  Make the number of 21 tickets the same.  LCM of 5 and 6 is 30.

1¹₅ = ⁶₅

Number of $21 tickets : $17 tickets = 6 : 5

	$21	$17	Total
Number	18 u	25 u
Value	$21	$17
Total value	378 u	425 u	$7227

Total amount collected from the sale of the sold tickets
= 378 u + 425 u
= 803 u

1 u = 7227 ÷ 803 = 9

Number of $21-tickets left unsold
= 12 u 
= 12 x 9
= 108

More amount to be collected if all the tickets were sold
= 108 x 21
= $2268

Answer(s): $2268