12 men do a work in 36 days.In how many days can 18 men do the same work? Sol:This can be solved as 1 man's can do work in 12*36 days So,1 man's 1 day work (1/12*36) days Hence 18 men's 1 day work is (18/12*36) So Days taken for 18 men is (12*36)/18 days.
Similarly Here is another question where i applied the same concept but i'm not getting the answer. Q)4 men or 8 women can do a work in 24 days.How many days will 12 men and 8 women work to do same work. My Soln: 4 men or 8 women do a work in 24 days. so 1 man can do work in (24*4) days. So 1 man's 1 day work is 1/(24*4) Hence 12 men and 8 women or 16 mens can do work in 16/(24*4) So days taken for 16 men to do work us (24*4)/16 days. But the actual answer is 3/2 days.