if 7 persons can do 7 times of a particular work in 7 days , then , 9 persons can do 9 times of that work in ?
that is , 1 person can do one time of the work in 7 days . therefore , 9 persons can do 9 times work in the same 7 days itself . option ' e '
divide(divide(multiply(7, 7), divide(7, 9)), 9)