Correct Answer - Option 2 : 1950 m
Given:
Speed of boat in still water = 17 km/h
Speed of the stream = 4 km/h
Time taken = 540 seconds
Formulas Used:
Speed = Distance/Time
1 km = 1000 meter
S(upstream) = S(boat in still water) - S(stream)
Calculation:
S(upstream) = S(boat in still water) - S(stream)
⇒ S(upstream) = (17 – 4)
⇒ S(upstream) = 13 km/hr
Speed = Distance/Time
⇒ Distance = Speed x Time
⇒ Distance = 13 x (540/3600) = 1.95 km = 1950 meter
∴ The distance travelled downstream is 1950 meter.
Conversion of Time from seconds to hours
1 second = (1/3600) hour
