Wand X together can complete a work in 40 days. X and Y together can complete the same work in 60 days. If W, X, and Y all work together, then the same work gets completed in 30 days. How many days will W and Y together take to complete the same work?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 40 days.
W and X together can complete a work in 40 days.
X and Y together can complete the same work in 60 days.
If W, X, and Y all work together, then the same work gets completed in 30 days
L.C.M(40, 60, and 30) = 120
The efficiency of W and X = 120/40 = 3 units
The efficiency of X and Y = 120/60 = 2 units
The efficiency of W, X, and Y = 120/30 = 4 units
Thus,
The efficiency of W = (W + X + Y) - (X + Y) = 4 - 2 = 2 units
The efficiency of X = 3 - 2 = 1 unit
The efficiency of Y = 2 - 1 = 1 unit
So,
Time taken by W and Y = 120/(2 + 1) = 120/3 = 40 days