At a safari park, each adult ticket cost $27 and each child ticket cost $11. On Friday, the number of adult tickets sold was 72 less than the number of child tickets. On Saturday, the number of adult tickets sold decreased by 45% while the number of child tickets sold increased by 50%. If a total of 1543 tickets were sold on Saturday, how much money was collected on Friday?

	Adult tickets	Child tickets	Total tickets
Before	1 u	1 u + 72	2 u + 72
Change	- 0.45 u	+ 0.5 u + 36
After	0.55 u	1.5 u + 108	2.05 u + 108

45% x 1 u = ⁴⁵₁₀₀ x 1 u = 0.45 u 
50% x 1 u = ⁵⁰₁₀₀ x 1 u = 0.5 u
50% x 72 = ⁵⁰₁₀₀ x 72 = 36

Number of tickets sold on Saturday
= 0.55 u + 1.5 u + 108
= 2.05 u + 108

2.05 u + 108 = 1543
2.05 u = 1543 - 108
2.05 u = 1435

1 u = 1435 ÷ 2.05 = 700

Amount collected from adult tickets on Friday
= 1 u x 27
= 700 x 27
= $18900

Amount collected from child tickets on Friday
= 11(1 u + 72)
= 11(700 + 72)
= 11 x 772
= $8492

Total amount collected on Friday
= 18900 + 8492
= $27392

Answer(s):$27392