A motor boat covers a given distance in 6 hours moving downstream in a...
Given information:
- Time taken to cover a distance downstream = 6 hours
- Time taken to cover the same distance upstream = 10 hours
Let's assume:
- Speed of the motor boat in still water = S km/hr
- Speed of the river current = C km/hr
Understanding the problem:
- When the motor boat moves downstream, it gets the additional speed of the river current, so the effective speed becomes (S + C) km/hr.
- When the motor boat moves upstream, it goes against the river current, so the effective speed becomes (S - C) km/hr.
Calculating the distance:
- Distance = Speed × Time
Downstream:
- Distance = (S + C) × 6
Upstream:
- Distance = (S - C) × 10
Since the distances covered downstream and upstream are the same, we can equate the two equations:
(S + C) × 6 = (S - C) × 10
Simplifying the equation:
6S + 6C = 10S - 10C
10C + 6C = 10S - 6S
16C = 4S
4C = S
Time taken to cover the same distance in still water:
We can substitute S = 4C in any of the distance equations to find the time.
Using the downstream distance equation:
Distance = (4C + C) × 6
Distance = 5C × 6
Distance = 30C
To find the time, we divide the distance by the speed:
Time = Distance / Speed
Time = 30C / (4C)
Time = 30 / 4
Time = 7.5 hours
Answer:
The time taken to cover the same distance in still water is 7.5 hours.
A motor boat covers a given distance in 6 hours moving downstream in a...
let..distance=dvelocity in still water=vvelocity of water flow=x..relative velocity (upstream)=v-×relative velocity (downstream)=v+xnow...d/(v+x)=6d/(v-×)=10...divide both and solve to getx=v/4...put it any of the above eqnd/(v+v/4)=64d/5v=6d/v= 15/2 ..ans= 15/2 hrs
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