The park tickets are priced at $12 and $5.  The number of $12-dollar tickets available is  1¹₃ that of the number of $5-dollar tickets. 3 out of 5 of the $12-dollar tickets and all the $5-dollar tickets were sold. The ticket sales amounted to $2628. How much more would have been collected if all the tickets were sold?

	$12	$5
Comparing $12 and $5 tickets at first	4x5 = 20 u	3x5 = 15 u
Before	5x4 = 20 u
Change	- 3x4 = - 12 u	- 15 u
After	2x4 = 8 u	0 u

The number of 12 tickets at first is repeated.  Make the number of 12 tickets the same.  LCM of 5 and 4 is 20.

1¹₃ = ⁴₃

Number of $12 tickets : $5 tickets = 4 : 3

	$12	$5	Total
Number	12 u	15 u
Value	$12	$5
Total value	144 u	75 u	$2628

Total amount collected from the sale of the sold tickets
= 144 u + 75 u
= 219 u

1 u = 2628 ÷ 219 = 12

Number of $12-tickets left unsold
= 8 u 
= 8 x 12
= 96

More amount to be collected if all the tickets were sold
= 96 x 12
= $1152

Answer(s): $1152