Correct Answer - Option 2 : 2
Given:
Speed of boat in still water = 13 km/h
Distance = 3 km
Time taken = 12 minutes
Formulas Used:
Speed = Distance/Time
S(downstream) = S(boat) + S(stream)
Calculation:
Speed = Distance/Time
⇒ S(downstream) = (3 x 60)/12
⇒ S(downstream) = 15 km/h
S(downstream) = S(boat) + S(stream)
⇒ S(stream) = S(downstream) – S(boat)
⇒ S(stream) = 15 – 13
⇒ S(stream) = 2 km/h
∴ The speed of stream is 2 km/h
Conversion of Time from minutes to hours
1 min = (1/60) hour