742 - Math - Problem Solving

Question: P can give Q a start of 20 seconds in a kilometer race. P can give R a start of 200 meters in the same kilometer race. And Q can give R a start of 20 seconds in the same kilometer race. How long does P take to run the kilometer?

1. 200 seconds
2. 240 seconds
3. 160 seconds
4. 140 seconds