Question
A man takes 10 hours to row 21 km upstream from point A
to point B and back to A by boat. If he takes the same time to row 7 km downstream as upstream. If it takes time to cover 3 kilometers then find the velocity of the stream and the speed of the boat in still water.Solution
Let the speed of boat in still water =B and speed of stream =S then Speed of boat in downstream=B+S and distance =7km So now -time =7/B+S Speed of boat upstream =B-S and Distance =3km So, time = 3/B-S ATQ- 3/(B-S)=7/(B+S) 7B-7S=3B+3S 4B=10S B =5S/2 
And Speed of boat in still water = B =5km/h Â
A boat takes 7 hours to cover 259 km upstream and 9 hours to cover 477 km downstream. Find the time taken by the boat to cover 645 km upstream and 660 k...
A boat covers 24km upstream and 36km downstream in 6 hours while it covers 36km upstream and 24km downstream in 13/2 hours. The speed of the Boat is.Â
The speed of the stream is 11 km/h. Boat ‘A’ covers 84 km distance against the stream in 6 hours and boat ‘B’ covers 90 km distance against the ...
When travelling downstream, a boat takes 4.25 hours to travel 204 km. If the speed of the stream is (3/8)th of downstream speed of the boat, ...
Covering 54 km upstream and 150 km downstream takes a boat 8 hours in total. The boat’s still-water speed is 18 km/h more than the stream. What is the...
A boat can travel 36 km downstream in 40 min. The ratio of the speed of the boat in still water to the speed of the stream is 5: 4. How much time will t...
A man can row at 36 km/hr in still water. In a stream which is flowing at 12 km/hr, it takes him 3 hrs to a place and back. How far is the place?
The ratio of the speed of the boat in upstream to that of in downstream is 3:4, respectively. If the speed of the current is 5 km/h, then find the speed...
A boat can cover 60 km in still water and 75 km in downstream in 4 hours and 3 hours respectively. Find the time taken by the boat to cover 60 km upstre...
A boat’s speed against the stream is 66.67% less than its speed in still water. If it covers 180 km downstream in 4 hours, find the time (in minutes) ...
Relevant for Exams:
