At a safari park, each adult ticket cost $40 and each child ticket cost $18. On Thursday, the number of adult tickets sold was 104 less than the number of child tickets. On Friday, the number of adult tickets sold decreased by 5% while the number of child tickets sold increased by 25%. If a total of 1230 tickets were sold on Friday, how much money was collected on Thursday?

	Adult tickets	Child tickets	Total tickets
Before	1 u	1 u + 104	2 u + 104
Change	- 0.05 u	+ 0.25 u + 26
After	0.95 u	1.25 u + 130	2.2 u + 130

5% x 1 u = ⁵₁₀₀ x 1 u = 0.05 u 
25% x 1 u = ²⁵₁₀₀ x 1 u = 0.25 u
25% x 104 = ²⁵₁₀₀ x 104 = 26

Number of tickets sold on Friday
= 0.95 u + 1.25 u + 130
= 2.2 u + 130

2.2 u + 130 = 1230
2.2 u = 1230 - 130
2.2 u = 1100

1 u = 1100 ÷ 2.2 = 500

Amount collected from adult tickets on Thursday
= 1 u x 40
= 500 x 40
= $20000

Amount collected from child tickets on Thursday
= 18(1 u + 104)
= 18(500 + 104)
= 18 x 604
= $10872

Total amount collected on Thursday
= 20000 + 10872
= $30872

Answer(s):$30872