Task: Question Answering
Input (English): Problem: at what price must an book costing $ 47.50 be marked in order that after deducting 20 % from the list price . it may be sold at a profit of 25 % on the cost price ? 
Options: a ) 72.5 , b ) 55.5 , c ) 64.2 , d ) 82.5 , e ) 60.5
Output (English): c