There's a boat traveling on a river. When it's going with the river flow, it takes 10 minutes to cover 1km, but when going against the flow, it takes it 15 minutes.
How long does it take to cover 1km when traveling in still water?
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Sign up to join this communityThere's a boat traveling on a river. When it's going with the river flow, it takes 10 minutes to cover 1km, but when going against the flow, it takes it 15 minutes.
How long does it take to cover 1km when traveling in still water?
The boat takes 12 min to cover 1km in still water.
Going downstream, the boat is moving at 6km/hr. Going upstream, it moves at 4km/hr. The difference is twice the speed of the river, which is flowing at 1km/hr.
So, the boat itself moves at 5km/hr in still water.
Answer:
It will never travel 1km in still water
Explanation
A river will never have still water, as a river by definition is a stream of water that flows into a larger body (a lake, or sea etc). Therefore it will never be still
Let x be the speed of boat and y be the speed of river flow.
Then
(x+y)*10 = 1
(x-y)*15 = 1
That is
(x+y)10 = (x-y)*15
which gives
y = x/5
No consider t be the time it will take to cover 1Km in still water.
Then
(x+y)*10 = x*t
(x+x/5)*10 = x*t
60x/5x = t
So we get t = 12
The boat will take 12 minutes to cover 1Km in still water.
let's calculate step by step
Downstream equation: speed of boat + speed of current = x + Y = 6
upstream equation: speed of boat - speed of current = x - Y = 4
On solving these two equations: speed of boat = 5Km/hr And thus it will take (1/5)hr or 12 mins to cover 1Km in still water.