If 12 men or 20 women can do a piece of work in 81 days, then in how many days can 9 men and 12 women together do the work?	Choose the correct choice from the following:
A) 10 days  B) 30 days  C) 20 days  D) 60 days  E) 40 days

Rationale: "d 60 days given that 12 m = 20 w = > 3 m = 5 w 9 men + 12 women = 15 women + 12 women = 27 women 20 women can do the work in 81 days . so , 27 women can do it in ( 20 * 81 ) / 27 = 60 days ."
Answer: D