At a museum, each adult ticket cost $23 and each child ticket cost $13. On Monday, the number of adult tickets sold was 180 less than the number of child tickets. On Tuesday, the number of adult tickets sold decreased by 15% while the number of child tickets sold increased by 10%. If a total of 1563 tickets were sold on Tuesday, how much money was collected on Monday?

	Adult tickets	Child tickets	Total tickets
Before	1 u	1 u + 180	2 u + 180
Change	- 0.15 u	+ 0.1 u + 18
After	0.85 u	1.1 u + 198	1.95 u + 198

15% x 1 u = ¹⁵₁₀₀ x 1 u = 0.15 u 
10% x 1 u = ¹⁰₁₀₀ x 1 u = 0.1 u
10% x 180 = ¹⁰₁₀₀ x 180 = 18

Number of tickets sold on Tuesday
= 0.85 u + 1.1 u + 198
= 1.95 u + 198

1.95 u + 198 = 1563
1.95 u = 1563 - 198
1.95 u = 1365

1 u = 1365 ÷ 1.95 = 700

Amount collected from adult tickets on Monday
= 1 u x 23
= 700 x 23
= $16100

Amount collected from child tickets on Monday
= 13(1 u + 180)
= 13(700 + 180)
= 13 x 880
= $11440

Total amount collected on Monday
= 16100 + 11440
= $27540

Answer(s):$27540