Correct Answer - Option 2 : 33 Days
Given:
Efficiency of P and Q = 2 ∶ 1
Efficiency of P and R = 3 ∶ 1
They all can complete work in days = 6
Calculation:
Efficiency ratio of P : Q : R = 6 : 3 : 2
Q P R
1 : 2
3 : 1
3 : 6 : 2
⇒ Work done by P in a day = 6x
⇒ Work done by Q in a day = 3x
⇒ Work done by R in a day = 2x
Total Work/Total work done by all in a day = Number of days
⇒ Total Work/(6x + 3x + 2x) = 6
⇒ Total Work = 66x
R alone will complete work in days = 66x/2x = 33 days
∴ R alone will complete work in 33 days.