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Question

What is the speed of the boat in still water?

I. It takes 2 hours to cover the distance between A and B downstream.

II. It takes 4 hours to cover the distance between A and B upstream.

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Solution

The correct option is **D** Data given in both the statements I and II together are not sufficient to answer the question.

Let the distance between A and B be z km.

Again, let the speed of the boat in still water be x kmph and that of the stream be y kmph.

∴ Rate downstream = (x+y) kmph

Rate upstream = (x-y) kmph

From statement I,

zx+y=2 …(i)

From statement II,

zx−y=4 …(ii)

We have two equations and three variables, therefore both equations are not sufficient.

Let the distance between A and B be z km.

Again, let the speed of the boat in still water be x kmph and that of the stream be y kmph.

∴ Rate downstream = (x+y) kmph

Rate upstream = (x-y) kmph

From statement I,

zx+y=2 …(i)

From statement II,

zx−y=4 …(ii)

We have two equations and three variables, therefore both equations are not sufficient.

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