Task: Question Answering
Input (English): Problem: a square mirror has exactly half the area of the rectangular wall on which it is hung . if each side of the mirror is 21 inches and the width of the wall is 28 inches , what is the length of the wall , in inches ? 
Options: a ) 21.5 , b ) 31.5 , c ) 41.5 , d ) 61.5 , e ) 71.5
Output (English): b