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

Quantitative Aptitude

BOATS AND STREAMS MCQs

Total Questions : 948 | Page 92 of 95 pages

Question 911. A boat is rowed downstream at 15.5km/hr and upstream at 8.5 km/hr. The speed of the stream is________?

3.5km/hr
5.75km/hr
6.5km/hr
7km/hr

Discuss Question

Answer: Option A. -> 3.5km/hr
SPEED DOWNSTREAM = 15.5 KM/HR,
SPEED UPSTREAM = 8.5 KM/HR
SPEED OF THE STREAM = ½ (15.5 – 8.5)KM = 3.5 KM/HR

Question 912. A boat running downstream covers 24 km’s in 4 hours while for covering the same distance upstream it takes 6 hours whats the speed of the boat in still water?

3.5km/hr
5.5 km/hr
6 km/hr
Data Inadequate
None of these

Discuss Question

Answer: Option E. -> None of these
SPEED DOWNSTREAM = 24/4 KM/HR = 6 KM/HR
SPEED UPSTREAM = 24/6 KM/HR = 4 KM/HR
SPEED OF THE BOAT IN STILL WATER = ½ (6 +4)KM/HR = 5 KM/HR

Question 913. A man can row 30 km downstream and 20 km upstream in 4 hours. He can row 45 km downstream and 40 km upstream in 7 hours. Find the speed of man in still water?

15 kmph
10 kmph
12 kmph
12.5 kmph
None of these

Discuss Question

Answer: Option D. -> 12.5 kmph
LET THE SPEED OF THE MAN IN STILL WATER BE A KMPH AND LET THE SPEED OF THE STREAM BE B KMPH.
NOW 30/(A + B) + 20/(A – B) = 4 AND 45/(A + B) + 40/(A – B) = 7
SOLVING THE EQUATION, THE SPEED OF MAN IN STILL WATER IS 12.5 KMPH.

Question 914. The time taken by a man to row his boat upstream is twice the time taken by him to row the same distance downstream. If the speed of the boat in still water is 42 kmph, find the speed of the stream?

12 kmph
13 kmph
14 kmph
15 kmph

Discuss Question

Answer: Option C. -> 14 kmph
THE RATIO OF THE TIMES TAKEN IS 2:1.
THE RATIO OF THE SPEED OF THE BOAT IN STILL WATER TO THE SPEED OF THE STREAM = (2+1)/(2-1) = 3/1 = 3:1
SPEED OF THE STREAM = 42/3 = 14 KMPH.

Question 915. The speed of a boat in upstream is 60 kmph and the speed of the boat downstream is 80 kmph. Find the speed of the boat in still water and the speed of the stream?

70, 10 kmph
35, 27 kmph
50, 60 kmph
45, 55 kmph

Discuss Question

Answer: Option A. -> 70, 10 kmph
SPEED OF THE BOAT IN STILL WATER = (60+80)/2 = 70 KMPH. SPEED OF THE STREAM = (80-60)/2 = 10 KMPH.

Question 916. The speed of a boat in still water is 60kmph and the speed of the current is 20kmph. Find the speed downstream and upstream?

35, 25 kmph
80, 40 kmph
40, 60 kmph
50, 55 kmph

Discuss Question

Answer: Option B. -> 80, 40 kmph
SPEED DOWNSTREAM = 60 + 20 = 80 KMPH
SPEED UPSTREAM = 60 – 20 = 40 KMPH

Question 917. A man rows his boat 85 km downstream and 45 km upstream, taking 2 1/2 hours each time. Find the speed of the stream?

5 kmph
6 kmph
7 kmph
8 kmph

Discuss Question

Answer: Option D. -> 8 kmph
SPEED DOWNSTREAM = D/T = 85/(2 1/2) = 34 KMPH
SPEED UPSTREAM = D/T = 45/(2 1/2) = 18 KMPH
THE SPEED OF THE STREAM = (34 – 18)/2 = 8 KMPH

Question 918. A man can row a boat at 20 kmph in still water. If the speed of the stream is 6 kmph, what is the time taken to row a distance of 60 km downstream?

20/6 hours
27/2 hours
30 hours
30/13 hours

Discuss Question

Answer: Option D. -> 30/13 hours
SPEED DOWNSTREAM = 20 + 6 = 26 KMPH.
TIME REQUIRED TO COVER 60 KM DOWNSTREAM = D/S = 60/26 = 30/13 HOURS.

Question 919. A man whose speed is 4.5 kmph in still water rows to a certain upstream point and back to the starting point in a river which flows at 1.5 kmph, find his average speed for the total journey?

8 kmph
4 kmph
2 kmph
10 kmph

Discuss Question

Answer: Option B. -> 4 kmph
M = 45
S = 1.5
DS = 6
US = 3
AS = (2 * 6 * 3) /9 = 4

Question 920. A man can row 6 kmph in still water. When the river is running at 1.2 kmph, it takes him 1 hour to row to a place and black. What is the total distance traveled by the man?