The zoo tickets are priced at $12 and $6.  The number of $12-dollar tickets available is  2⁴₅ that of the number of $6-dollar tickets. 3 out of 7 of the $12-dollar tickets and all the $6-dollar tickets were sold. The ticket sales amounted to $1020. How much more would have been collected if all the tickets were sold?

	$12	$6
Comparing $12 and $6 tickets at first	14x1 = 14 u	5x1 = 5 u
Before	7x2 = 14 u
Change	- 3x2 = - 6 u	- 5 u
After	4x2 = 8 u	0 u

The number of 12 tickets at first is repeated.  Make the number of 12 tickets the same.  LCM of 7 and 14 is 14.

2⁴₅ = ¹⁴₅

Number of $12 tickets : $6 tickets = 14 : 5

	$12	$6	Total
Number	6 u	5 u
Value	$12	$6
Total value	72 u	30 u	$1020

Total amount collected from the sale of the sold tickets
= 72 u + 30 u
= 102 u

1 u = 1020 ÷ 102 = 10

Number of $12-tickets left unsold
= 8 u 
= 8 x 10
= 80

More amount to be collected if all the tickets were sold
= 80 x 12
= $960

Answer(s): $960