# Aptitude - Boats and Streams

### Exercise :: Boats and Streams - Data Sufficiency 1

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.

 A. I alone sufficient while II alone not sufficient to answer B. II alone sufficient while I alone not sufficient to answer C. Either I or II alone sufficient to answer D. Both I and II are not sufficient to answer E. Both I and II are necessary to answer

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).

2.

 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.

 A. I alone sufficient while II alone not sufficient to answer B. II alone sufficient while I alone not sufficient to answer C. Either I or II alone sufficient to answer D. Both I and II are not sufficient to answer E. Both I and II are necessary to answer

Explanation:

Let AB = x km.

 I. Speed downstream = x km/hr 2

 II. Speed upstream = x km/hr. 4

 Speed of boat in still water = 1 x + x km/hr. 2 2 4

Thus, I and II both even do not give the answer. Correct answer is (D).

3.

 What is the speed of the boat in still water? I. The boat covers a distance of 48 kms in 6 hours while running upstream. II. The boat covers the same distance in 4 hours while running downstream.

 A. I alone sufficient while II alone not sufficient to answer B. II alone sufficient while I alone not sufficient to answer C. Either I or II alone sufficient to answer D. Both I and II are not sufficient to answer E. Both I and II are necessary to answer

Explanation:

 I. Speed upstream = 48 km/hr = 8 km/hr. 6

 II. Speed downstream = 48 km/hr = 12 km/hr. 4

 Speed of the boat = 1 (8 + 12) km/hr = 10 km/hr. 2

Thus, I and II together give the answer. Correct answer is (E).