Boats And Streams(Quantitative Aptitude ) Questions and answers for exam Preparation

Quantitative Aptitude

BOATS AND STREAMS MCQs

Total Questions : 948 | Page 91 of 95 pages

Question 901. . 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.

I and II only
All I, II and III
III, and either I or II
Any two of the three

Discuss Question

Answer: Option D. -> Any two of the three

Question 902. . 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.

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 necessary to answer

Discuss Question

Answer: Option D. -> Both I and II are necessary to answer

Question 903. A steamer goes downstream from one port to another in 4 hours, it covers the same distance upstream in 5 hours. If the speed of the stream is 2km/hr,the distance between the two parts is_______?

50km
60km
70km
80 km

Discuss Question

Answer: Option D. -> 80 km
LET THE DISTANCE BETWEEN THE TWO PARTS BE X KM.
THEN SPEED DOWNSTREAM = X/4 KM/HR.
SPEED UPSTREAM = X/5 KM/HR
SPEED OF THE STREAM = ½ (X/4 –X/5)
THEREFORE, ½(X/4 –X/5) = 2. => X/4 –X/5 = 4 => X = 80.
HENCE, THE DISTANCE BETWEEN THE TWO PORTS IS 80KM.

Question 904. The speed of a motor boat is that of the current of water as 36:5. The boat goes along with the current in 5 hours 10 min, it will come back in_______?

5 hours 50 min
6 hours
6 hours 50 min
12 hours 10 min

Discuss Question

Answer: Option C. -> 6 hours 50 min
LET THE SPEED OF MOTOR BOAT BE 36X KM/HR AND THAT OF CURRENT OF WATER BE 5X KM/HR
SPEED DOWNSTREAM = (36X +5X)KM/HR = 41X KM/HR
SPEED UPSTREAM = (36 -5X)KM/HR = 31X KM/HR
DISTANCE COVERED DOWNSTREAM = (41X × 31/6)KM
DISTANCE UPSTREAM = [1271X/6 × 1/31X]HRS
= 41/6 HRS = 6HRS 50 MIN

Question 905. A boat covers a distance of 30 km in 2 ½ hours running downstream while returning it covers the same distance in 3 ¾ hours. What is the speed of the boat in still water?

8km/hr
12km/hr
14 km/hr
15 km/hr
None of these

Discuss Question

Answer: Option E. -> None of these
SPEED DOWNSTREAM = (30 X 2/5)KM/HR = 12KM/HR
SPEED UPSTREAM = (30 X 4/15) KM/HR = 8 KM/HR
SPEED OF BOAT IN STILL WATER = ½ (12 + 8)KM/HR = 10 KM/HR

Question 906. A boat goes 24 km downstream in 10 hours, it takes 2 hours more to cover the same distance against the stream. What is the speed of the boat in still water?

2km/hr
2.8 km/hr
4 km/hr
4.2 km/hr
None of these

Discuss Question

Answer: Option E. -> None of these
SPEED DOWNSTREAM = 24/10 KM/HR = 2.4 KM/HR
SPEED UPSTREAM = 24/12 KM/HR = 2 KM/HR
SPEED OF THE BOAT IN STILL WATER = ½ (2.4 +2)KM/HR = 2.2 KM/HR

Question 907. The speed of a boat in still water is 5 km/hr, it can go 30km upstream and return downstream to the original point in 4 hours 30 min. The speed of the stream is_______?

5km/hr
8 km/hr
10 km/hr
15 km/hr

Discuss Question

Answer: Option A. -> 5km/hr
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 908. A person can row at 9 kmph and still water. He takes 4 1/2 hours to row from A to B and back. What is the distance between A and B if the speed of the stream is 1 kmph?

32 km
25 km
28 km
24 km
None of these

Discuss Question

Answer: Option E. -> None of these
LET THE DISTANCE BETWEEN A AND B BE X KM.
TOTAL TIME = X/(9 + 1) + X/(9 – 1) = 4.5
=> X/10 + X/8 = 9/2 => (4X + 5X)/40 = 9/2 => X = 20 KM.

Question 909. A man can row downstream at 18 kmph and upstream at 10 kmph. Find the speed of the man in still water and the speed of stream respectively?

13, 3
12, 6
15, 3
14, 4

Discuss Question

Answer: Option D. -> 14, 4
LET THE SPEED OF THE MAN IN STILL WATER AND SPEED OF STREAM BE X KMPH AND Y KMPH RESPECTIVELY.
GIVEN X + Y = 18 — (1)
AND X – Y = 10 — (2)
FROM (1) & (2) 2X = 28 => X = 14, Y = 4.

Question 910. The speed at which a man can row a boat in still water is 15 kmph. If he rows downstream, where the speed of current is 3 kmph, what time will he take to cover 60 metres?

10 seconds
15 seconds
20 seconds
12 seconds
None of these

Discuss Question

Answer: Option D. -> 12 seconds
SPEED OF THE BOAT DOWNSTREAM = 15 + 3 = 18 KMPH
= 18 * 5/18 = 5 M/S
HENCE TIME TAKEN TO COVER 60 M = 60/5 = 12 SECONDS.