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

Quantitative Aptitude

BOATS AND STREAMS MCQs

Total Questions : 948 | Page 93 of 95 pages

Question 921. The current of a stream runs at the rate of 4 kmph. A boat goes 6 km and back to the starting point in 2 hours, then find the speed of the boat in still water?

10 kmph
21 kmph
8 kmph
12 kmph

Discuss Question

Answer: Option C. -> 8 kmph
S = 4
M = X
DS = X + 4
US = X – 4
6/(X + 4) + 6/(X – 4) = 2
X = 8

Question 922. The current of a stream at 1 kmph. A motor boat goes 35 km upstream and back to the starting point in 12 hours. The speed of the motor boat in still water is_________?

6 kmph
7 kmph
8.5 kmph
8 kmph

Discuss Question

Answer: Option A. -> 6 kmph
S = 1
M = X
DS = X + 1
US = X – 1
35/(X + 1) + 35/(X – 1) = 12
X = 6

Question 923. 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. How far is the place?

3.12 km
2.88 km
3 km
2 km

Discuss Question

Answer: Option B. -> 2.88 km
M = 6
S = 1.2
DS = 6 + 1.2 = 7.2
US = 6 – 1.2 = 4.8
X/7.2 + X/4.8 = 1
X = 2.88

Question 924. A boat goes 100 km downstream in 10 hours, and 75 m upstream in 15 hours. The speed of the stream is________?

7 km/h
5 km/h
3 km/h
2 (1/2) km/h

Discuss Question

Answer: Option D. -> 2 (1/2) km/h
100 — 10 DS = 10
? —- 1
75 —- 15 US = 5
? —– 1 S = (10 – 5)/2
= 2 2 ½ KMPH

Question 925. A man can swim in still water at 4.5 km/h, but takes twice as long to swim upstream than downstream. The speed of the stream is_________?

3
7.5
2.25
1.5

Discuss Question

Answer: Option D. -> 1.5
M = 4.5
S = X
DS = 4.5 + X
US = 4.5 + X
4.5 + X = (4.5 – X)2
4.5 + X = 9 -2X
3X = 4.5
X = 1.5

Question 926. A boat can move upstream at 25 kmph and downstream at 35 kmph, then the speed of the current is_________?

5 kmph
10 kmph
30 kmph
15 kmph

Discuss Question

Answer: Option A. -> 5 kmph
US = 25
DS = 35
M = (35 – 25)/2 = 5

Question 927. A man can row with a speed of 15 kmph in still water. If the stream flows at 5 kmph, then the speed in downstream is________?

10 kmph
5 kmph
20 kmph
22 kmph

Discuss Question

Answer: Option C. -> 20 kmph
M = 15
S = 5
DS = 15 + 5 = 20

Question 928. A man swims downstream 30 km and upstream 18 km taking 3 hours each time, what is the speed of the man in still water?

2 kmph
8 kmph
16 kmph
4 kmph

Discuss Question

Answer: Option B. -> 8 kmph
30 — 3 DS = 10
? —- 1
18 —- 3 US = 6
? —- 1 M = ?
M = (10 + 6)/2 = 8

Question 929. A person can swim in still water at 4 km/h. If the speed of water 2 km/h, how many hours will the man take to swim back against the current for 6km?