On Monday, 300 more women than men attended a concert. On Tuesday, the number of women decreased by 50% and the number of men increased by 80%. 1415 audience attended the concert on Tuesday. If each ticket cost $12, how much money was collected from the sale of concert tickets on Monday?

	Women		Men
Comparing between the women and the men at first	300 more
Before	2x5	+ 300	5x2
Change	- 1x5	- 150	+ 4x2
After	1x5	+ 150	9x2

	Women		Men
Before	10 u + 300		10 u
Change	- 5 u - 150		+ 8 u
After	5 u + 150		18 u

50% = ⁵⁰₁₀₀ = ¹₂

80% = ⁸⁰₁₀₀ = ⁴₅

50% x 300
= ⁵⁰₁₀₀ x 300
= 150

300 - 150 = 150

Total number of tickets sold on Tuesday 
= 5 u + 150 + 18 u
= 23 u + 150 

23 u + 150 = 1415
23 u = 1415 - 150
23 u = 1265

1 u = 1265 ÷ 23 = 55

Total number of tickets sold on Monday
= 10 u + 300 + 10 u 
= 20 u + 300
= 20 x 55 + 150
= 1250

Amount collected from the sale of concert tickets on Monday
= 1250 x 12
= $15000

Answer(s): $15000