Task: Question Answering
Input (English): Problem: 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 ? 
Options: a ) $ 200 , b ) $ 400 , c ) $ 500 , d ) $ 800 , e ) $ 1000
Output (English): c