The museum tickets are priced at $22 and $20.  The number of $22-dollar tickets available is  1²₃ that of the number of $20-dollar tickets. 3 out of 4 of the $22-dollar tickets and all the $20-dollar tickets were sold. The ticket sales amounted to $1710. How much more would have been collected if all the tickets were sold?

	$22	$20
Comparing $22 and $20 tickets at first	5x4 = 20 u	3x4 = 12 u
Before	4x5 = 20 u
Change	- 3x5 = - 15 u	- 12 u
After	1x5 = 5 u	0 u

The number of 22 tickets at first is repeated.  Make the number of 22 tickets the same.  LCM of 4 and 5 is 20.

1²₃ = ⁵₃

Number of $22 tickets : $20 tickets = 5 : 3

	$22	$20	Total
Number	15 u	12 u
Value	$22	$20
Total value	330 u	240 u	$1710

Total amount collected from the sale of the sold tickets
= 330 u + 240 u
= 570 u

1 u = 1710 ÷ 570 = 3

Number of $22-tickets left unsold
= 5 u 
= 5 x 3
= 15

More amount to be collected if all the tickets were sold
= 15 x 22
= $330

Answer(s): $330