The speed of a boat in still water is 15km/h and the speed of the current is 9km/h. The distance travelled by the boat downstream in 25 minutes is:
- A8 km
- B10 km
- C12 km
- D9 km
Solution & Step-by-step Explanation
Speed of the boat in still water (u) =15km/h
Speed of the current (v) =9km/h
The speed downstream (D
s
) is given by:
D
s
=u+v=15+9=24km/h
Given Time =25minutes=
60
25
hours=
12
5
hours
Distance travelled downstream is:
Distance=Speed downstream×Time
Distance=24×
12
5
=2×5=10km
Speed of the current (v) =9km/h
The speed downstream (D
s
) is given by:
D
s
=u+v=15+9=24km/h
Given Time =25minutes=
60
25
hours=
12
5
hours
Distance travelled downstream is:
Distance=Speed downstream×Time
Distance=24×
12
5
=2×5=10km