The museum tickets are priced at $19 and $17.  The number of $19-dollar tickets available is  1¹₂ that of the number of $17-dollar tickets. 3 out of 4 of the $19-dollar tickets and all the $17-dollar tickets were sold. The ticket sales amounted to $921. How much more would have been collected if all the tickets were sold?

	$19	$17
Comparing $19 and $17 tickets at first	3x4 = 12 u	2x4 = 8 u
Before	4x3 = 12 u
Change	- 3x3 = - 9 u	- 8 u
After	1x3 = 3 u	0 u

The number of 19 tickets at first is repeated.  Make the number of 19 tickets the same.  LCM of 4 and 3 is 12.

1¹₂ = ³₂

Number of $19 tickets : $17 tickets = 3 : 2

	$19	$17	Total
Number	9 u	8 u
Value	$19	$17
Total value	171 u	136 u	$921

Total amount collected from the sale of the sold tickets
= 171 u + 136 u
= 307 u

1 u = 921 ÷ 307 = 3

Number of $19-tickets left unsold
= 3 u 
= 3 x 3
= 9

More amount to be collected if all the tickets were sold
= 9 x 19
= $171

Answer(s): $171