A 0.2 ft3 pressure cooker has an operating pressure of 40 psia. Initially, 50% of the volume

Question:

A 0.2 ft3 pressure cooker has an operating pressure of 40 psia. Initially, 50% of the volume is filled with vapor and the rest with liquid water. Determine.
The heat transfer necessary to vaporize all the water in the cooker.
What-if scenario: What would the heat transfer be if initially 20% of the volume were filled with vapor?