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 2 of 5.
Jagannath sahu said:
6 years ago
We have 48km in 14 hrs means 3km/he speed.
Now if we add and subtract stream of 1km/hr, then we will get 4km and 3km respectively.
So, the answer is 1km/hr.
Now if we add and subtract stream of 1km/hr, then we will get 4km and 3km respectively.
So, the answer is 1km/hr.
(1)
Sunny said:
6 years ago
48/4 = 12.
48/3 = 16.
12+16 = 14.
Or, 1 = 1/2.
Sp down = 4/1/2 = 8kmph, sp up=3/1/2=6kmph.
Sp of stream = 1/2 (8-6) = 1kmph.
48/3 = 16.
12+16 = 14.
Or, 1 = 1/2.
Sp down = 4/1/2 = 8kmph, sp up=3/1/2=6kmph.
Sp of stream = 1/2 (8-6) = 1kmph.
(1)
Nikalus said:
2 years ago
Thank you all for explanation
(1)
Nessa said:
9 years ago
How did you get x = 1/2? I got it as 2.
Priya said:
9 years ago
Distance=48 km in 14 hours.
rate of stream = x.
downstream=4 km (with the water).
Upstream =3 km(against the water).
Rate of the stream =1/2(4-3)=1/2.
Therefore x=1/2.
Then,4/1/2 =4 * 2 = 8.
Then,3/1/2 = 3 * 2 = 6.
So,1/2(8-6) = 1/2(2)
Answer is 1.
rate of stream = x.
downstream=4 km (with the water).
Upstream =3 km(against the water).
Rate of the stream =1/2(4-3)=1/2.
Therefore x=1/2.
Then,4/1/2 =4 * 2 = 8.
Then,3/1/2 = 3 * 2 = 6.
So,1/2(8-6) = 1/2(2)
Answer is 1.
Shanur Rahman said:
9 years ago
Suppose it took him x hrs to go downstream, then it will take him 14-x upstream. Therefore x/ (14-x) = 3/4.
There you go.
There you go.
Subhrasubha priyadarsini said:
8 years ago
4/x+y=3/x-y,
4x-4y=3x+,
x=7y -----> eq1
48/x+y +48/x-y =14,
48/8y+48/6y=14,
14/y=14,
y=1,
Now x=7.
4x-4y=3x+,
x=7y -----> eq1
48/x+y +48/x-y =14,
48/8y+48/6y=14,
14/y=14,
y=1,
Now x=7.
Divya said:
8 years ago
Given : 4/x+y = 3/x-y --> (1).
by solving the eq > x =7y.
and : 48/x-y + 48/x+y = 14.
48//7y-y + 48/7y+y = 14.
48/6y + 48/8y = 14.
8 + 6 =14y,
14 =14y,
y = 1km/hr.
by solving the eq > x =7y.
and : 48/x-y + 48/x+y = 14.
48//7y-y + 48/7y+y = 14.
48/6y + 48/8y = 14.
8 + 6 =14y,
14 =14y,
y = 1km/hr.
Pouvanam said:
9 years ago
How do you find the value of x?
Rya said:
8 years ago
Total distance is 48 that means he travels 24km downstream and 24km upstream, why we are taking the whole 48km to calculate the separate down and upstream time? Please tell me.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers