If P, Q, R can do a piece of work in 4 days, 8 days and 12 days respectively. If all of them work together, how long will they take to complete the work?
Answer: Option B
Solution: According to the above given formula, P and Q can do a work in x days, Q and R can do the same work in y days, P and R can do it in z days. If they all work together P, Q, R can do that work in days.
Hence, if all of them work together, the work will be completed in 2.18 days