one woman and one man can build a wall together in one hour , but the woman would need the help of two girls in order to complete the same job in the same amount of time . if one man and one girl worked together , it would take them two hours to build the wall . assuming that rates for men , women and girls remain constant , how many hours would it take one woman , one man , and one girl , working together , to build the wall ?
solution : let work done by man , women and girl per hour be m , w , g respectively . then , m + w = 1 / 1 - - > ( 1 ) , w + 2 g = 1 / 1 - - > ( 2 ) and m + g = 1 / 2 - - > ( 3 ) . no . of hours it would take forone woman , one man , and one girl , working together , to build the wall , n = 1 / m + w + g from ( 1 ) and ( 2 ) , m = 2 g and from ( 3 ) g = 1 / 6 , m = 1 / 3 and w = 2 / 3 . so , n = 1 / ( 7 / 6 ) = 6 / 7 option , b
add(add(const_2, const_2), const_3)