An ambulance moving at 40 ms sounds its siren whose

Question

Compute the each part of given problem:

Problem: An ambulance moving at 40 m/s sounds its siren whose frequency is 440 Hz. A car is moving in the same direction as the ambulance at 20 m/s.

Part I: What frequency does a person in the car hear as the ambulance approaches the car?

Hz

Part II: What frequency does a person in the car hear after the ambulance passes the car?

Hz

I need proficient help in the above problem.