Aptitude - Boats and Streams - Discussion

Discussion Forum : Boats and Streams - Data Sufficiency 1 (Q.No. 1)
Directions to Solve

Each of the questions given below consists of a statement and / or a question and two statements numbered I and II given below it. You have to decide whether the data provided in the statement(s) is / are sufficient to answer the given question. Read the both statements and

  • Give answer (A) if the data in Statement I alone are sufficient to answer the question, while the data in Statement II alone are not sufficient to answer the question.
  • Give answer (B) if the data in Statement II alone are sufficient to answer the question, while the data in Statement I alone are not sufficient to answer the question.
  • Give answer (C) if the data either in Statement I or in Statement II alone are sufficient to answer the question.
  • Give answer (D) if the data even in both Statements I and II together are not sufficient to answer the question.
  • Give answer(E) if the data in both Statements I and II together are necessary to answer the question.

1.

A boat takes a total time of three hours to travel downstream from P and Q and upstream back from Q to P. What is the speed of the boat in still water?

I. 

The speed of the river current is 1 km per hour.

 II. 

The distance between P and Q is 4 km.

I alone sufficient while II alone not sufficient to answer
II alone sufficient while I alone not sufficient to answer
Either I or II alone sufficient to answer
Both I and II are not sufficient to answer
Both I and II are necessary to answer
Answer: Option
Explanation:

 I. Speed of the current = 1 km/hr.

II. PQ = 4 km.

Let the speed of the boat in still water be x km/hr. Then,

4 + 4 = 3. This gives x.
(x + 1) (x - 1)

Correct answer is (E).

Discussion:
9 comments Page 1 of 1.

Bhumit saxena said:   1 year ago
3 = D(X+Y) + D(X-Y).
So, only statement 2 is enough to get ans.
As DY cancels.
Where speed = dis/time.
So time=speed*dis.
Total Time = downstream speed * dis + upstream speed * dis.

Amit kumar said:   4 years ago
@Bhawana,

Here we are asked to tell which of the following statements are necessary to answer the question,

So here in order to Calculate the speed of the boat in still water, we are required distance and speed of the stream, hence both the statements are necessary,

Or we can say that data in both statements is necessary to answer the question.

Bhawana sharma said:   4 years ago
I'm not getting it. Can anybody please explain it.

Abc said:   8 years ago
Total time is given in words as three, not in the options observed clearly.

Ijas said:   8 years ago
Could you please help me, how can we find if there is no. 1 & 4?

Rajesh said:   8 years ago
Thanks for giving explanation. It is helpful my examination.

Inder said:   9 years ago
Where is the total time given?

Mukesh said:   1 decade ago
Going with downstream the speed of the boat is (x+1) , while.
Going with upstream the speed of the boat is (x-1) ,
Total time = 3 hours,
Acc. To equation,
time = distance/speed (x+1) + distance/speed (x-1).
3 = (4/x+1) + (4/x-1).

Vasumaila said:   1 decade ago
I can't understand, any one of here please do needful.

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