Discussion
Home ‣ Aptitude ‣ Boats and Streams Comments
- Question
- The speed of a boat in still water is 10 km/h. If it can travel 26 km downstream and 14 km upstream in the same time , then the speed of stream is?
Options- A. 2 km/h
- B. 2.5 km/h
- C. 3 km/h
- D. None of these
- Correct Answer
- 3 km/h
ExplanationLet the speed of the stream = x km/h
?Speed of boat in still water = 10 km/h
Speed of boat downstream = ( x + 10) km/h
Speed of boat upstream=(10 - x) km/h
? Time taken to travel 26 km downstream=[ 26 / ( 10 + x ) ] h
Time taken to travel 14 km upstream=[ 14 /( 10 - x )] h
? By condition [ 26 / ( 10 + x)]=[ 14 / ( 10 - x)]
? 26(10-x)=14(10+x)
? 260-26x =140 + 14x
? 40x=120
? x = 3 Here, speed of stream = 3 km/h - 1. The speed of boat upstream and speed of boat downstream are 7 km/h and 13 km/h, respectively. Then the speed of stream and the speed of boat in still water is?
Options- A. 10 km/h and 3 km/h
- B. 15 km/h and 9 km/h
- C. 20 km/h and 6 km/h
- D. 40 km/h and 12 km/h Discuss
- 2. Mr Jaspal purchased a cow for Rs. 3,000 and sold it to Mr Dharampal, on the same day, for Rs. 3,600, allowing Dharampal a credit of 2 years. If the rate of interest be 10% per annum, then the Jaspal has a gain of:
Options- A. Nil
- B. 5%
- C. 750
- D. 10% Discuss
- 3. The profit earned by Mrs Malhotra in selling an article for Rs. 900 is double the loss incurred by her when the same article is sold for Rs. 490. At what price (Rs.) should the article be sold to make 25% profit?
Options- A. 715
- B. 469
- C. 400
- D. 750 Discuss
- 4. The banker's discount on a sum of money for 3 years is Rs. 1116. The true discount on the same sum for 4 years is Rs. 1200. What is the rate percent?
Options- A. 8%
- B. 12%
- C. 10%
- D. 6% Discuss
- 5. The banker's gain on a sum due 6 years hence at 12% per annum is Rs. 540. What is the banker's discount?
Options- A. 1240
- B. 1120
- C. 1190
- D. 1290 Discuss
- 6. A boat goes 40 km. upstream in 8 hours and 36 km. downstream in 6 hours. The speed of the boat in standing water is?
Options- A. 6.5 km.hr
- B. 6 km/hr
- C. 5.5 km/hr
- D. 5 km/hr Discuss
- 7. If a man's rate with the current is 12 km/hr and the rate of the current is 1.5 km/hr then man's rate against the current is?
Options- A. 9 km/hr
- B. 6.75 km/hr
- C. 5.25 km/hr
- D. 7.5 km/hr Discuss
- 8. If a man rows at 5 km/hr in still water and 3.5 km/hr against the current his rate along the current is?
Options- A. 8.5 km/hr
- B. 6.5 km/hr
- C. 6 km/hr
- D. 4.25 km/hr Discuss
- 9. The speed of a boat downstream is 15 km/hr and the speed of the stream is 1.5 km/hr. The speed of the boat upstream is?
Options- A. 13.5 km/hr
- B. 16.5 km/hr
- C. 12 km/hr
- D. 8.25 km/hr Discuss
- 10. The speed of a boat in still water is 2km/hr. If its speed upstream be 1 km/hr, then speed of the stream is?
Options- A. 1.5 km/hr
- B. 3 km/hr
- C. 1 km/hr
- D. None of these Discuss
Boats and Streams problems
Search Results
Correct Answer: 10 km/h and 3 km/h
Explanation:
Rate in still water=[(1/2)(u+v)] km/h
Rate of current=[(1/2)(u-v)] km/h
where u= speed of boat in downstream
v=speed of boat in upstream
Speed of boat in still water=[(1/2)(7+13)] =10 km/h
Speed of the stream =[(1/2)(13-7)]=3 km/h
Correct Answer: Nil
Explanation:
Correct Answer: 750
Explanation:
Correct Answer: 6%
Explanation:
Correct Answer: 1290
Explanation:
Correct Answer: 5.5 km/hr
Explanation:
Speed upstream = (40/8) km/hr = 5 km/hr
Speed downstream = (36/6) km/hr = 6 km/hr
Speed of boat in still water = (5 + 6)/2 km/hr = 5.5 km/hr.
Correct Answer: 9 km/hr
Explanation:
Let the rate against the current be x km/hr.
Then, (12 - x) / 2 = 1.5
? 12 - x = 3
? x = 9 km/hr
Correct Answer: 6.5 km/hr
Explanation:
Speed of current = 5 - 3.5 = 1.5 km/hr.
So the speed of man along the current = 5 + 1.5 = 6.5 km/hr
Correct Answer: 12 km/hr
Explanation:
Let the speed of boat in still water be x km/hr
Then, x + 1.5 = 15
? x = 13.5
? Speed upstream = (13.5 - 1.5) km/hr = 12 km/hr
Correct Answer: 1 km/hr
Explanation:
Let the speed of stream be x km/hr
Then, speed upstream = (2 - x ) km/hr
? 2 - x = 1
? x = 1 km/hr
Comments
There are no comments.More in Aptitude:
Programming
Copyright ©CuriousTab. All rights reserved.