Correct Answer - Option 1 : 120 km/h
Given:
A woman goes from place S to place T at the speed of 150 km/hr and return at the speed of 100 km/hr.
Concepts used:
Average speed = (2S1 × S2)/(S1 + S2)
S1 → Speed at which a woman travelled from place S to T
S2 → Speed at which a woman returned from place T to S.
Calculation:
Average speed = (2S1 × S2)/(S1 + S2)
⇒ 2 × 150 × 100/(150 + 100)
⇒ 30000/250
⇒ 120 km/h
∴ Average speed in whole journey is 120 km/hr.
