Question : P, Q, and R alone can do a piece of work in 5, 6, and 4 days, respectively. All three of them began the work together but Q left 1 day before completion of the work. In how many days was the work completed?
Option 1:
Option 2:
Option 3:
Option 4:
Correct Answer:
Solution :
Let the total number of days be t.
Rate of P =
Rate of Q =
Rate of R =
⇒ Combined rate =
Q leaves 1 day before the completion of the work.
So, P, Q, and R worked together for (t – 1) days, and P and R worked on the last day.
Total work = 1 =
⇒ 1 –
⇒
⇒
⇒
⇒ t =
Hence, the correct answer is
