X can do a piece of work in 14 days, Y can complete the same work in 28 days, and Z can do it in 42 days. In how many days can X, Y, and Z together complete the work?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. .
Total work = 84 (LCM of 14, 28, and 42)
Efficiency of X = 84/14 = 6
Efficiency of Y = 84/28 = 3
Efficiency of Z = 84/42 = 2
Total efficiency = 6 + 3 + 2 = 11
Time required for X, Y, and Z = 84/11 = days
Therefore, X, Y, and Z together can complete the work in days.