On Thursday, 550 more men than women attended a concert. On Friday, the number of men decreased by 40% and the number of women increased by 50%. 645 audience attended the concert on Friday. If each ticket cost $8, how much money was collected from the sale of concert tickets for the two days?

	Men		Women
Comparing between the men and the women at first	550 more
Before	5x2	+ 550	2x5
Change	- 2x2	- 220	+ 1x5
After	3x2	+ 330	3x5

	Men		Women
Before	10 u + 550		10 u
Change	- 4 u - 220		+ 5 u
After	6 u + 330		15 u

40% = ⁴⁰₁₀₀ = ²₅

50% = ⁵⁰₁₀₀ = ¹₂

40% x 550
= ⁴⁰₁₀₀ x 550
= 220

550 - 220 = 330

Total number of tickets sold on Friday 
= 6 u + 330 + 15 u
= 21 u + 330 

21 u + 330 = 645
21 u = 645 - 330
21 u = 315

1 u = 315 ÷ 21 = 15

Total number of tickets sold for the two days
= (10 u + 550) + 10 u + (6 u + 330) + 15 u
= 41 u + 880
= 41 x 15 + 880
= 1495

Amount collected from the sale of concert tickets for the two days
= 1495 x 8
= $11960

Answer(s): $11960