The Velocity Ratio (VR) of a block and tackle system of two pulleys with the effort in the upward direction is:

3

Reason — In a block and tackle system, the velocity ratio (V.R.) is equal to the number of strands of the rope supporting the moving block. When the system has two pulleys and the effort is applied in the upward direction, there are 3 supporting strands.

Therefore, the velocity ratio is 3.