Discussion
Home ‣ Aptitude ‣ Boats and Streams Comments
- Question
- A boat goes 48 km downstream in 20 h. It takes 4 h more to cover the same distance against the stream. What is the speed of the boat in still water?
Options- A. 2.2 km/h
- B. 2 km/h
- C. 4 km/h
- D. 4.2 km/h
- Correct Answer
- 2.2 km/h
ExplanationSpeed downstream = 48/20 = 2.4 km/h
Speed upstream = 48/24 = 2 km/h
? Speed of boat in still water = (Speed downstream + Speed upstream)/2
= (2.4 + 2)/2 = 4.4/2 = 2.2 km/h - 1. A swimmer's speed downstream is 11 km/h and speed of the stream is 1.5 km/h. Find the upstream speed of swimmer.?
Options- A. 8 km/h
- B. 9.5 km/h
- C. 9 km/h
- D. 6. 25 km/h Discuss
- 2. If the speed of swimmer in still water is 9 km/h. Find the downstream speed of the swimmer, when the river is flowing with the speed of 6 km/h.?
Options- A. 15 km/h
- B. 18 km/h
- C. 3 km/h
- D. 12 km/h Discuss
- 3. When the speed of a boat in still water is 4 km/h and the rate of stream is 2 km/h, find upstream speed of the boat.?
Options- A. 6 km/h
- B. 5 km/h
- C. 2 km/h
- D. 7 km/h Discuss
- 4. A man rows downstream 60 km and upstream 36 km, taking 4 hours each time. The speed of the man is :
Options- A. 15 km/h
- B. 16 km/h
- C. 8 km/h
- D. 12 km/h Discuss
- 5. A man can row upstream at 15 km/h and downstream at 21 km/h. The speed of water current of the river is?
Options- A. 8 km/h
- B. 6 km/h
- C. 3 km/h
- D. 5 km/h Discuss
- 6. Keshav can row 60 km downstream and 36 km upstream, taking 10 h each time. What is the velocity of the current?
Options- A. 3 km/h
- B. 2. 2 km/h
- C. 4 km/h
- D. 1.2 km/h Discuss
- 7. What time will be taken by a boat to cover a distance of 128 km along the stream, if speed of a boat in still water is 24 km/h and speed of stream is 8 km/h?
Options- A. 8 km/h
- B. 4 km/h
- C. 7 km/h
- D. 6 km/h Discuss
- 8. A boat goes 12 km upstream in 48 minutes. The speed of stream is 2 km/hr. The speed of boat in still water is?
Options- A. 13 km/hr
- B. 2.25 km/hr
- C. 17 km/hr
- D. 15 km/hr Discuss
- 9. The current of a stream runs at the rate of 4 km/hr. A boat goes 6 km and back to the starting point in 2 hours. The speed of the boat in still water is?
Options- A. 6 km/hr
- B. 7.5 km/hr
- C. 8 km/hr
- D. 6.8 km/hr Discuss
- 10. A boat moves upstream at the rate of 1 km in 10 minutes and downstream at the rate of 1 km in 6 minutes. The speed of the current is?
Options- A. 1 km/hr
- B. 1.5 km/hr
- C. 2 km/hr
- D. 2.5 km/hr Discuss
Boats and Streams problems
Search Results
Correct Answer: 8 km/h
Explanation:
Rate of stream = ( Speed downstream - Speed upstream )/2
? 1.5 = (11 - Speed upstream)/2
? 11 - Speed upstream = 3
? Speed upstream = 11 - 3 = 8 km/h
Correct Answer: 15 km/h
Explanation:
Speed downstream = Swimmer'S speed in still water + Rate of stream
= 9 + 6 = 15 km/h
Correct Answer: 2 km/h
Explanation:
Upstream speed of boat = Boat's speed in still water - Rate of stream = 4 - 2 = 2 km/h
Correct Answer: 12 km/h
Explanation:
Sd = 15 km/h
Su = 9 km/h
Speed of man= (Sd + Su)/2
? Speed of man = (15 + 9)/ 2 = 12 km/h
Correct Answer: 3 km/h
Explanation:
Speed of water current =( Vd - Vu)/2
= (21 - 15) /2
= 3 km/h
Correct Answer: 1.2 km/h
Explanation:
Speed upstream = Distance/Time = 60/10 = 6 km/h
Speed upstream = Distance/Time = 36/10 = 3.6 km/h
? Velocity of the current = (speed downstream - Speed upstream)/2
= (6 - 3.2)/2 = 1.2 km/h
Correct Answer: 8 km/h
Explanation:
Downstream speed of boat = Speed of boat in still water + Speed of stream
= 24 + 8 = 32 km/h
? Required time = Distance/Speed downstream
= 128/32 = 4 km/h
Correct Answer: 17 km/hr
Explanation:
? (12 x 60)/48 = (L - 2)
? L = 15 + 2 = 17 km/hr
Correct Answer: 8 km/hr
Explanation:
Let the speed in still water be x km/hr
Then, 6/x + 4 + 6/x - 4 = 2
? 6[ x - 4 + x + 4] = 2(x2 - 16)
? x2 - 6x - 16 = 0
? (x - 8) (x + 2) = 0
? x = 8 km/hr
Correct Answer: 2 km/hr
Explanation:
Speed upstream = 6 km/hr
Speed downstream = 10 km/hr
? Speed of the current = (10 - 6)/2 km/hr = 2 km/hr
Comments
There are no comments.More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.