Problems on Boats and Streams Part 2

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.
 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)
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.
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.

Directions to Solve
Each of the questions given below consists of a question followed by three statements. You have to study the question and the statements and decide which of the statement(s) is/are necessary to answer the question.
1.
 What is the speed of the boat in still water? I. The speed downstream is 12 kmph. II. The speed upstream is 4 kmph. III. In a to and fro journey between two points, the average speed of the boat was 6 kmph.
 A. I and II only B. All I, II and III C. III, and either I or II D. Any two of the three E. None of these