Aman stands still on a moving escalator and a woman walks past him in the same direction as the escalator. to a stationary observer the man has a speed of 0.2 m/s and the woman has a speed of 0.5 m/s from the frame or reference of the man on the escalator how fast is the woman walking?

Let Ve =  speed of escalator
Let  Vm = speed of the man (Vm=0 because he is stationary)
Let Vw =  speed of woman

According to the stationary observer,
Because the man stands still on the escalator, his speed is Ve = 0.2 m/s.
The speed of the woman is Ve + Vw = 0.5 m/s

Therefore
0.2 + Vw = 0.5
Vw = 0.3 m/

The woman is walking at 0.3 m/s.