The bird park tickets are priced at $19 and $9.  The number of $19-dollar tickets available is  2¹₅ that of the number of $9-dollar tickets. 2 out of 5 of the $19-dollar tickets and all the $9-dollar tickets were sold. The ticket sales amounted to $4501. How much more would have been collected if all the tickets were sold?

	$19	$9
Comparing $19 and $9 tickets at first	11x5 = 55 u	5x5 = 25 u
Before	5x11 = 55 u
Change	- 2x11 = - 22 u	- 25 u
After	3x11 = 33 u	0 u

The number of 19 tickets at first is repeated.  Make the number of 19 tickets the same.  LCM of 5 and 11 is 55.

2¹₅ = ¹¹₅

Number of $19 tickets : $9 tickets = 11 : 5

	$19	$9	Total
Number	22 u	25 u
Value	$19	$9
Total value	418 u	225 u	$4501

Total amount collected from the sale of the sold tickets
= 418 u + 225 u
= 643 u

1 u = 4501 ÷ 643 = 7

Number of $19-tickets left unsold
= 33 u 
= 33 x 7
= 231

More amount to be collected if all the tickets were sold
= 231 x 19
= $4389

Answer(s): $4389