The theme park tickets are priced at $17 and $15.  The number of $17-dollar tickets available is  2¹₃ that of the number of $15-dollar tickets. 2 out of 5 of the $17-dollar tickets and all the $15-dollar tickets were sold. The ticket sales amounted to $2778. How much more would have been collected if all the tickets were sold?

	$17	$15
Comparing $17 and $15 tickets at first	7x5 = 35 u	3x5 = 15 u
Before	5x7 = 35 u
Change	- 2x7 = - 14 u	- 15 u
After	3x7 = 21 u	0 u

The number of 17 tickets at first is repeated.  Make the number of 17 tickets the same.  LCM of 5 and 7 is 35.

2¹₃ = ⁷₃

Number of $17 tickets : $15 tickets = 7 : 3

	$17	$15	Total
Number	14 u	15 u
Value	$17	$15
Total value	238 u	225 u	$2778

Total amount collected from the sale of the sold tickets
= 238 u + 225 u
= 463 u

1 u = 2778 ÷ 463 = 6

Number of $17-tickets left unsold
= 21 u 
= 21 x 6
= 126

More amount to be collected if all the tickets were sold
= 126 x 17
= $2142

Answer(s): $2142