Turbine engine/pressurization

Question 1

At 20000 feet with a cabin altitude of 2000 ft, the outflow valve is suddenly opened completely. What will happen to the cabin altitude?

Answer 1

Increase to FL200

Question 2

At 20000 feet with a cabin altitude of 2000 ft, the outflow valve is opened. What will happen to the cabin pressure?

Answer 2

Decrease

Question 3

w=Where does the ECS get pressurized air from?

Answer 3

Engine compressors