At a florist shop on a certain day, all corsages sold for either $20 or $30. If 8 of the corsages that sold for $30 had instead sold for $20, then the store's revenue from corsages that day would have been reduced by 35 percent. What was the store's actual revenue from corsages that day?
Pick one: A) $ 320 B) $ 400 C) $ 600 D) $ 800 E) $ 1000

Rationale: i am doing it elaborately , hope it will help you . let , no . of corsages @ $ 20 = x , no . of corsages @ $ 30 = y and revenue = r so , 20 x + 30 y = r . . . . . . . . . ( 1 ) now , given the situation , 20 ( x + 8 ) + 30 ( y - 8 ) = r - . 25 r = > 20 x + 160 + 30 y - 240 = . 75 r = > 20 x + 30 y = . 75 r + 80 . . . . . . . . . . . . ( 2 ) so , r = . 75 r + 80 = > r = 320 the answer is a .
Answer: A