Aptitude - Boats and Streams - Discussion
Discussion Forum : Boats and Streams - General Questions (Q.No. 11)
11.
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?
Answer: Option
Explanation:
| Rate downstream = |  |
1 | x 60 |  km/hr = 6 km/hr. |
| 10 |
Rate upstream = 2 km/hr.
| Speed in still water = | 1 | (6 + 2) km/hr = 4 km/hr. |
| 2 |
 Required time = |
|
5 | hrs = 1 |
1 | hrs = 1 hr 15 min. |
| 4 | 4 |
Discussion:
27 comments Page 2 of 3.
Lohith said:
10 years ago
s = d/t;
u-v = 2/1;
u-v = 2.
u+v = 2/10/60.
u+v = 12.
u = 7.
v = 5.
Final value = 5/7 which is less than a hour.
u-v = 2/1;
u-v = 2.
u+v = 2/10/60.
u+v = 12.
u = 7.
v = 5.
Final value = 5/7 which is less than a hour.
Sravankumar said:
1 decade ago
We caluculate required time by using this formule
t=l/s.
Here t=5km/4hrs leads to (5/4)km per hour
t=l/s.
Here t=5km/4hrs leads to (5/4)km per hour
Darth vadar said:
9 years ago
Divide 5 by 4 we get 0.25. So why the answer is 1 hr 15 min instead of 1 hr 25 min.
Kiran said:
8 years ago
The ans must be 1hr 25mins.
5/4=1.25.
How it can be 1hr 15mins?
5/4=1.25.
How it can be 1hr 15mins?
(2)
Ibrana said:
6 years ago
Please discuss the proper way to find required time.
Kessy said:
5 years ago
Anyone, please explain this step 1/2 times (6 + 2).
Thomas said:
6 years ago
I also agree, The answer should be 1h and 25 mins.
(3)
Sonia said:
8 years ago
1hr = 60mins.
So, 1/4 of 1 hr = 1/4*60= 15min.
So, 1/4 of 1 hr = 1/4*60= 15min.
Hasi said:
3 months ago
I agree that the answer will be 1 hour 25 min.
Kas said:
1 decade ago
How to calculate the required time ?
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers