A boat covers a certain distance downstream in 1 hour, while it comes back in 1�

CuriousTab

CuriousTab

Home Aptitude

Discussion

Home ‣ Aptitude ‣ Boats and Streams Comments

Question
A boat covers a certain distance downstream in 1 hour, while it comes back in 1½ hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?
Options
A. 12 kmph
B. 13 kmph
C. 14 kmph
D. 15 kmph
E. None of these

Correct Answer

15 kmph

Explanation
Let the speed of the boat in still water be x kmph. Then,

Speed downstream = (x + 3) kmph,

Speed upstream = (x - 3) kmph.

∴ (x + 3) x 1 = (x - 3) x	3
	2

⟹ 2x + 6 = 3x - 9

⟹ x = 15 kmph.

Boats and Streams problems

Search Results

1. A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:
Options
A. 2 mph
B. 2.5 mph
C. 3 mph
D. 4 mph

2. A motorboat, whose speed in 15 km/hr in still water goes 30 km downstream and comes back in a total of 4 hours 30 minutes. The speed of the stream (in km/hr) is:
Options
A. 4
B. 5
C. 6
D. 10

3. A boat running downstream covers a distance of 16 km in 2 hours while for covering the same distance upstream, it takes 4 hours. What is the speed of the boat in still water?
Options
A. 4 km/hr
B. 6 km/hr
C. 8 km/hr
D. Data inadequate

4. A man can row at 5 kmph in still water. If the velocity of current is 1 kmph and it takes him 1 hour to row to a place and come back, how far is the place?
Options
A. 2.4 km
B. 2.5 km
C. 3 km
D. 3.6 km

5. A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is:
Options
A. 8.5 km/hr
B. 9 km/hr
C. 10 km/hr
D. 12.5 km/hr

6. The speed of a boat in still water in 15 km/hr and the rate of current is 3 km/hr. The distance travelled downstream in 12 minutes is:
Options
A. 1.2 km
B. 1.8 km
C. 2.4 km
D. 3.6 km

7. A boatman goes 2 km against the current of the stream in 1 hour and goes 1 km along the current in 10 minutes. How long will it take to go 5 km in stationary water?
Options
A. 40 minutes
B. 1 hour
C. 1 hr 15 min
D. 1 hr 30 min

8. A man rows to a place 48 km distant and come back in 14 hours. He finds that he can row 4 km with the stream in the same time as 3 km against the stream. The rate of the stream is:
Options
A. 1 km/hr
B. 1.5 km/hr
C. 2 km/hr
D. 2.5 km/hr

9. Speed of a boat in standing water is 9 kmph and the speed of the stream is 1.5 kmph. A man rows to a place at a distance of 105 km and comes back to the starting point. The total time taken by him is:
Options
A. 16 hours
B. 18 hours
C. 20 hours
D. 24 hours

10. In one hour, a boat goes 11 km/hr along the stream and 5 km/hr against the stream. The speed of the boat in still water (in km/hr) is:
Options
A. 3 km/hr
B. 5 km/hr
C. 8 km/hr
D. 9 km/hr

Comments

More in Aptitude: