Aptitude - Boats and Streams - Discussion
Discussion Forum : Boats and Streams - General Questions (Q.No. 2)
2.
A man's speed with the current is 15 km/hr and the speed of the current is 2.5 km/hr. The man's speed against the current is:
Answer: Option
Explanation:
Man's rate in still water = (15 - 2.5) km/hr = 12.5 km/hr.
Man's rate against the current = (12.5 - 2.5) km/hr = 10 km/hr.
Discussion:
72 comments Page 2 of 8.
Mani said:
1 decade ago
Here they did not mention that is/clearly not questioned that this is a boad and stream problem.
Suraj said:
1 decade ago
Thanks balaji.
Prasad said:
1 decade ago
How do we know the man is traveling in boat with out mention in the question?
Raj said:
1 decade ago
The speed of man is 15 including the speed of current.
Actual speed of man is 12. 5,
And now against the current 12. 5-2. 5 (speed of current) =10.
Actual speed of man is 12. 5,
And now against the current 12. 5-2. 5 (speed of current) =10.
Sapna said:
1 decade ago
Solve acc to formula,
We have
Current=1/2(a-b).
So,
2.5=1/2(15-b).
2.5*2=15-b.
b=10km/hr.
We have
Current=1/2(a-b).
So,
2.5=1/2(15-b).
2.5*2=15-b.
b=10km/hr.
Karthik said:
1 decade ago
The actual speed is 12.5. Due to downstream it becomes 15 (adding 2.5) and due to upstream it becomes 10 (subtracting 2.5). Simple no confusions.
Atuljain said:
1 decade ago
Downstream = speed of the man + speed of the stream.
15 = x+2.5.
x = 12.5.
Upstream = speed of the man - speed of the stream.
x = 12.5-2.5.
x = 10.
15 = x+2.5.
x = 12.5.
Upstream = speed of the man - speed of the stream.
x = 12.5-2.5.
x = 10.
Arun.D said:
1 decade ago
Man's speed with the current = 15 km/hr.
Speed of the current = 2.5 km/hr.
Man's speed against the current=?
Downstream = (u+v)km/hr.
u+v = 15.
v = 2.5.
u+2.5 = 15.
u = 15-2.5.
u = 12.5km/hr.
Upstream = (u-v)km/hr.
= (12.5-2.5)km/hr.
= 10km/hr.
Speed of the current = 2.5 km/hr.
Man's speed against the current=?
Downstream = (u+v)km/hr.
u+v = 15.
v = 2.5.
u+2.5 = 15.
u = 15-2.5.
u = 12.5km/hr.
Upstream = (u-v)km/hr.
= (12.5-2.5)km/hr.
= 10km/hr.
Ramakrishna said:
1 decade ago
Given that mans speed with current means mans speed+current = 15, So here current is given from which we get actual speed of man is 12.5km/hr, Then he asked against the current so the answer will be 12.5 - 2.5=10km/hr.
Vijaya said:
1 decade ago
Hi. Guyz. I have one doubt. ? how we know. The given question is upstream or downstream. I can't understand that. If you don't mind can you please tell me that.
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