The bird park tickets are priced at $21 and $11.  The number of $21-dollar tickets available is  2¹₄ that of the number of $11-dollar tickets. 2 out of 5 of the $21-dollar tickets and all the $11-dollar tickets were sold. The ticket sales amounted to $1196. How much more would have been collected if all the tickets were sold?

	$21	$11
Comparing $21 and $11 tickets at first	9x5 = 45 u	4x5 = 20 u
Before	5x9 = 45 u
Change	- 2x9 = - 18 u	- 20 u
After	3x9 = 27 u	0 u

The number of 21 tickets at first is repeated.  Make the number of 21 tickets the same.  LCM of 5 and 9 is 45.

2¹₄ = ⁹₄

Number of $21 tickets : $11 tickets = 9 : 4

	$21	$11	Total
Number	18 u	20 u
Value	$21	$11
Total value	378 u	220 u	$1196

Total amount collected from the sale of the sold tickets
= 378 u + 220 u
= 598 u

1 u = 1196 ÷ 598 = 2

Number of $21-tickets left unsold
= 27 u 
= 27 x 2
= 54

More amount to be collected if all the tickets were sold
= 54 x 21
= $1134

Answer(s): $1134