at a florist shop on a certain day , all corsages sold for either $ 20 or $ 30 . if 10 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 20 percent . what was the store ' s actual revenue from corsages that day ?
"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 + 10 ) + 30 ( y - 10 ) = r - . 2 r = > 20 x + 200 + 30 y - 300 = . 8 r = > 20 x + 30 y = . 8 r + 100 . . . . . . . . . . . . ( 2 ) so , r = . 8 r + 100 = > r = 500 the answer is c ."
subtract(divide(negate(subtract(multiply(20, 10), multiply(30, 10))), divide(20, const_100)), subtract(multiply(20, 10), multiply(30, 10)))