Correct Answer: 2 hrs
Explanation:
Given Prabhas is twice as good a workman as Rana.
Prabhas finishes the work in 3 hrs
=> Rana finishes the work in 6 hrs.
Number of hours required together they could finish the work
= 3 x 6 / 3 + 6
= 18/9
= 2 hrs.
