Aptitude - Boats and Streams - Discussion
Discussion Forum : Boats and Streams - General Questions (Q.No. 15)
15.
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:
Answer: Option
Explanation:
Suppose he move 4 km downstream in x hours. Then,
| Speed downstream = |  |
4 |  |
km/hr. |
| x |
| Speed upstream = | |
3 | |
km/hr. |
| x |
 |
48 | + | 48 | = 14 or x = | 1 | . |
| (4/x) | (3/x) | 2 |
So, Speed downstream = 8 km/hr, Speed upstream = 6 km/hr.
| Rate of the stream = | 1 | (8 - 6) km/hr = 1 km/hr. |
| 2 |
Discussion:
49 comments Page 3 of 5.
Surya said:
7 years ago
the speed of an up stream=x+y/2;
the speed of a down stream=x-y/2;
So they have given like 4km with the stream and 3km against the stream so
x+y/2=4;
x+y=8------------(1);
x-y=6-------------(2);
---------
2y=2;
-----------
y=1 rate of stream;
the speed of a down stream=x-y/2;
So they have given like 4km with the stream and 3km against the stream so
x+y/2=4;
x+y=8------------(1);
x-y=6-------------(2);
---------
2y=2;
-----------
y=1 rate of stream;
Mandal shuvo said:
7 years ago
Let rate upstream be x and downstream be x/2 then required ratio be 3x/4:x/4 = 3 : 1 is answer.
Patchala.lokesh said:
7 years ago
Very simple it takes 3km/hr to travel down stream and 4km/hr to travel upstream so the difference b/w 4-3=1 is the rate of stream.
Kajal said:
6 years ago
I'm not understanding this one I mean I don't get 1/2 by solving the equation.
Avula venkata said:
2 days ago
Good questions, thanks.
Padma said:
1 decade ago
I am not able to understand why x=1/2 and,
Speed downstream = (4/x).
Speed upstream = (3/x).
Can anyone clear my doubt?
Speed downstream = (4/x).
Speed upstream = (3/x).
Can anyone clear my doubt?
Ram said:
2 decades ago
I'm also having this doubt. Anybody help me.
Manish said:
2 decades ago
We know that x=1/2, put this value in speed downstream= (4/x) then we get speed down stream=8km/h similarly we get speed upstream.
Manish said:
2 decades ago
Speed of down stream is always greater than upstream because in down stream the gravitational force enhence some speed of the stream.
Rohit said:
1 decade ago
Is there any other solotion without assuming the x ?
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