Task: Question Answering
Input (English): Problem: a tailor trims 11 feet from opposite edges of a square piece of cloth , and 7 feet from the other two edges . if 84 square feet of cloth remain , what was the length of a side of the original piece of cloth ? 
Options: a ) 26 , b ) 27 , c ) 28 , d ) 29 , e ) 30
Output (English): c