Z1, Z2, and Z3 can do work in 100, 50 and 75 days respectively. All three of them began the work together but Z2 left 15 days before the completion of the work. In how many days was the work completed?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is Option 3 i.e. 30 days.
Z1, Z2, and Z3 can do work in 100, 50, and 75 days respectively
L.C.M(100, 50, and 75) = 300
The efficiency of Z1 = 300/100 = 3 units
The efficiency of Z2 = 300/50 = 6 units
The efficiency of Z3 = 300/75 = 4 units
Let the total number of days be n
⇒ (3 + 6 + 4)n + 6(n - 15) = 300
⇒ 13n + 6n - 90 = 300
⇒ 19n = 390
⇒ n = 30
So, the total days to complete the work is 30 days