Correct Answer - Option 1 : 6 km/hr
Given:
Speed of boat in still water = 9 km/h
Speed of stream = 3 km/h
Formula Used:
Upstream speed = Speed of boat in still water – Speed of stream
Downstream speed = Speed of boat in still water + Speed of stream
Calculation:
Upstream speed = 9 – 3 = 6 km/h
Downstream speed = 9 + 3 = 12 km/h
Difference between the downstream speed and upstream speed = 12 – 6 = 6 km/h
∴ The difference between the upstream and downstream speed is 6 km/h.
