The park tickets are priced at $9 and $5.  The number of $9-dollar tickets available is  2¹₃ that of the number of $5-dollar tickets. 3 out of 4 of the $9-dollar tickets and all the $5-dollar tickets were sold. The ticket sales amounted to $2739. How much more would have been collected if all the tickets were sold?

	$9	$5
Comparing $9 and $5 tickets at first	7x4 = 28 u	3x4 = 12 u
Before	4x7 = 28 u
Change	- 3x7 = - 21 u	- 12 u
After	1x7 = 7 u	0 u

The number of 9 tickets at first is repeated.  Make the number of 9 tickets the same.  LCM of 4 and 7 is 28.

2¹₃ = ⁷₃

Number of $9 tickets : $5 tickets = 7 : 3

	$9	$5	Total
Number	21 u	12 u
Value	$9	$5
Total value	189 u	60 u	$2739

Total amount collected from the sale of the sold tickets
= 189 u + 60 u
= 249 u

1 u = 2739 ÷ 249 = 11

Number of $9-tickets left unsold
= 7 u 
= 7 x 11
= 77

More amount to be collected if all the tickets were sold
= 77 x 9
= $693

Answer(s): $693