Aptitude - Boats and Streams - Discussion
Discussion Forum : Boats and Streams - General Questions (Q.No. 10)
10.
A boat covers a certain distance downstream in 1 hour, while it comes back in 1
hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?
hours. If the speed of the stream be 3 kmph, what is the speed of the boat in still water?
Answer: Option
Explanation:
Let the speed of the boat in still water be x kmph. Then,
Speed downstream = (x + 3) kmph,
Speed upstream = (x - 3) kmph.
 (x + 3) x 1 = (x - 3) x |
3 |
| 2 |
2x + 6 = 3x - 9
x = 15 kmph.
Discussion:
20 comments Page 2 of 2.
Natraj said:
7 years ago
The speed of the boat in still water formula is 1/2(a-b) right then why there is no usage of formula here.
(1)
MADHURI WAGHALE said:
1 decade ago
D1 = D2.
SO, U = X.
A = X+3, B = X-3.
A*T1 = B*T2.
HERE, T1 = 1, T2 = 3/2.
THEREFORE,
X=U=15KMPH.
SO, U = X.
A = X+3, B = X-3.
A*T1 = B*T2.
HERE, T1 = 1, T2 = 3/2.
THEREFORE,
X=U=15KMPH.
SAnil said:
1 decade ago
Why we not take ?
3/x+3 + 3/x-3 = 5/2 ( total hrs = 1 hrs + 1 1/2 hrs)
3/x+3 + 3/x-3 = 5/2 ( total hrs = 1 hrs + 1 1/2 hrs)
(3)
Hardik raj said:
3 years ago
Why we have not taken total time as 5/2? Please explain it.
Swapnagolla said:
7 years ago
Why we taken x-3 why can't 3-x?
Please explain me.
Please explain me.
(1)
Ali said:
1 decade ago
@Rehman how you can do in short cut way?
RAHAMAN said:
1 decade ago
SHORT-CUT
90-60=30/2=15KMH
90-60=30/2=15KMH
Subha.R said:
9 years ago
Is there any shortcut way?
Kartikey said:
1 decade ago
Please explain in detail.
Dushyant Singh said:
7 years ago
Yes, right @Suraj Dev.
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