Problem: a metallic sheet is of rectangular shape with dimensions 30 m x 25 m . from each of its corners , a square is cut off so as to make an open box . if the length of the square is 6 m , the volume of the box ( in m cube ) is : 
Options: a ) 920 m cube , b ) 840 m cube , c ) 1000 m cube , d ) 120 m cube , e ) none of these
e