Correct Answer - Option 1 : 16 km
Given:
Man travelled 61 km in 9 hours
Walking speed = 4 km/h
Bicycle speed = 9 km/h
Formula Used:
Distance = Speed × Time
Calculation:
Let the time taken by man by walking be t hours
Time taken by the man by bicycle = (9 – t) hours
(4 km/h)(t h) + (9 km/h)(9 – t) h = 61 km
⇒ 4t + 81 – 9t = 61
⇒ 5t = 20
⇒ t = 4
Distance covered by man by walking = 4 h × 4km/h
⇒ 16 km
∴ The distance covered by man by walking is 16 km.