The tourist attraction tickets are priced at $30 and $20.  The number of $30-dollar tickets available is  2¹₆ that of the number of $20-dollar tickets. 2 out of 3 of the $30-dollar tickets and all the $20-dollar tickets were sold. The ticket sales amounted to $7980. How much more would have been collected if all the tickets were sold?

	$30	$20
Comparing $30 and $20 tickets at first	13x3 = 39 u	6x3 = 18 u
Before	3x13 = 39 u
Change	- 2x13 = - 26 u	- 18 u
After	1x13 = 13 u	0 u

The number of 30 tickets at first is repeated.  Make the number of 30 tickets the same.  LCM of 3 and 13 is 39.

2¹₆ = ¹³₆

Number of $30 tickets : $20 tickets = 13 : 6

	$30	$20	Total
Number	26 u	18 u
Value	$30	$20
Total value	780 u	360 u	$7980

Total amount collected from the sale of the sold tickets
= 780 u + 360 u
= 1140 u

1 u = 7980 ÷ 1140 = 7

Number of $30-tickets left unsold
= 13 u 
= 13 x 7
= 91

More amount to be collected if all the tickets were sold
= 91 x 30
= $2730

Answer(s): $2730