A fire truck travels at a speed of 83 km/h with its siren emitting sound at a frequency of 480 Hz.

A fire truck travels at a speed of 83 km/h with its siren emitting sound at a frequency of 480 Hz. What is the frequency heard by a passenger in a car traveling at 67 km/h in the oncoming lane to the fire truck at the following times? [Hint: Take the speed of sound to be 354 m/s. (It is a hot day.)]