Aptitude - Boats and Streams - Discussion
Discussion Forum : Boats and Streams - General Questions (Q.No. 13)
13.
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:
Answer: Option
Explanation:
Speed upstream = 7.5 kmph.
Speed downstream = 10.5 kmph.
 Total time taken = |
 |
105 | + | 105 |  hours = 24 hours. |
| 7.5 | 10.5 |
Discussion:
24 comments Page 1 of 3.
Ramya said:
1 decade ago
How do you arrive at upstream and down stream speed.
Bhavana said:
1 decade ago
How do you calculate upstream and downstream speed?
Bhavana said:
1 decade ago
Speed upstream is 9+1.5 and downstream is 9-1.5.
I think generally in stream sums we should calculate first the upstream and the downstream values.
I think generally in stream sums we should calculate first the upstream and the downstream values.
Kau said:
1 decade ago
You are wrong Bhavana, you have written opposite.
Raju said:
1 decade ago
Time taken for up stream = 105/(9-1.5)=14h
Time taken for down stream =
105/(9+1.5)=10h Total time taken= 14+10=24h
Time taken for down stream =
105/(9+1.5)=10h Total time taken= 14+10=24h
(1)
Rakesh KIIT said:
1 decade ago
Average speed During the Journey = (2*(9+1.5)*(9-1.5))/(9+1.5)+
(9-1.5)
so,Average speed=8.75 kmph
so,Total time= total distance/average speed
=(105*2)/8.75
= 24 hours.
(9-1.5)
so,Average speed=8.75 kmph
so,Total time= total distance/average speed
=(105*2)/8.75
= 24 hours.
Abhi poojary said:
1 decade ago
Just calculate downstream. 10 hours. Upstream has to be more than 10. So only 24 possible.
Gego Georoge said:
1 decade ago
I have a doubt, 9 km in question is speed of Boat, and a man rows 105 km but his speed is not given, and we have to find time taken by man.
Sidheswar sahoo said:
1 decade ago
9 km/hr is the speed of boat in standing water.
Boat has to move twice the distance of 105km to reach at same point.
Then (105/9)+(105/9) = 23.33333333333333333.
Then It should be 24hr.
Boat has to move twice the distance of 105km to reach at same point.
Then (105/9)+(105/9) = 23.33333333333333333.
Then It should be 24hr.
Saran said:
1 decade ago
Speed of boat in still water is 9km how could you consider it as upstream speed similarly to downstream also they couldn't mention anything like that. Please explain.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers