The museum tickets are priced at $20 and $14.  The number of $20-dollar tickets available is  1¹₂ that of the number of $14-dollar tickets. 3 out of 4 of the $20-dollar tickets and all the $14-dollar tickets were sold. The ticket sales amounted to $3504. How much more would have been collected if all the tickets were sold?

	$20	$14
Comparing $20 and $14 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 20 tickets at first is repeated.  Make the number of 20 tickets the same.  LCM of 4 and 3 is 12.

1¹₂ = ³₂

Number of $20 tickets : $14 tickets = 3 : 2

	$20	$14	Total
Number	9 u	8 u
Value	$20	$14
Total value	180 u	112 u	$3504

Total amount collected from the sale of the sold tickets
= 180 u + 112 u
= 292 u

1 u = 3504 ÷ 292 = 12

Number of $20-tickets left unsold
= 3 u 
= 3 x 12
= 36

More amount to be collected if all the tickets were sold
= 36 x 20
= $720

Answer(s): $720