P, Q and R can complete a piece of work in 9, 12 and 18 days, respectively. Working together, how much work can they complete in one day?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. .
P can complete the work = 9 days
So P's one-day work = 1/9
Q can complete the work = 12 days
So Q's one-day work = 1/12
R can complete the work = 18 days
So R's one-day work = 1/18
The total work they can complete together in one day = 1/9 + 1/12 + 1/18
⇒ 4/36 + 3/36 + 2/36 = 9/36 = 1/4