The safari park tickets are priced at $18 and $11.  The number of $18-dollar tickets available is  2⁵₆ that of the number of $11-dollar tickets. 2 out of 3 of the $18-dollar tickets and all the $11-dollar tickets were sold. The ticket sales amounted to $9720. How much more would have been collected if all the tickets were sold?

	$18	$11
Comparing $18 and $11 tickets at first	17x3 = 51 u	6x3 = 18 u
Before	3x17 = 51 u
Change	- 2x17 = - 34 u	- 18 u
After	1x17 = 17 u	0 u

The number of 18 tickets at first is repeated.  Make the number of 18 tickets the same.  LCM of 3 and 17 is 51.

2⁵₆ = ¹⁷₆

Number of $18 tickets : $11 tickets = 17 : 6

	$18	$11	Total
Number	34 u	18 u
Value	$18	$11
Total value	612 u	198 u	$9720

Total amount collected from the sale of the sold tickets
= 612 u + 198 u
= 810 u

1 u = 9720 ÷ 810 = 12

Number of $18-tickets left unsold
= 17 u 
= 17 x 12
= 204

More amount to be collected if all the tickets were sold
= 204 x 18
= $3672

Answer(s): $3672