please help, i have done the part a and b but i don't know how to do part c.

An air-track glider attached to a spring oscillates between the 3.00 cm mark and the 50.0 cm mark on the track. The glider completes 10.0 oscillations in 36.0 s. What is the period of the oscillations? 3.6 s
What is the frequency of the oscillations? 0.278 Hz
What is the angular frequency of the oscillation?

angular frequency= 2PI*frequency.