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:
8.5 km/hr
9 km/hr
10 km/hr
12.5 km/hr
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 4 of 8.

Ravi said:   9 years ago
Well said @Mani.

Roshni yadav said:   9 years ago
Thank you @Balaji.

Arjun said:   9 years ago
Well explain by Mani and Balaji.

Ramu said:   9 years ago
Thank you @Balaji.

Shahid said:   8 years ago
Very good explanation, thank you all.

Arun said:   8 years ago
Stream direction is same while man's direction is opposite in the case of upstream.

Then why we subtract stream instead of the man's speed?

Swathi said:   8 years ago
Why can't we use the formula 1/2 (a-b) to get the upstream value directly?

That time the answer would be 20 km/hr. Please tell me.

Shyam said:   8 years ago
@Vishal.

15 is the speed of the man "with" speed of current i.e., 15 is the speed of man in downstream.
That means M + S = 15; S = 2.5.
Finally, man's speed =15-2.5 = 12.5.

Sibani said:   8 years ago
Is both the terms rate of stream and speed of the current are same.
If both are same I am getting 12.5 as an answer for this question, can anyone clarify it?

Mahima said:   8 years ago
Thank you @Balaji. You explained it very clearly.


Post your comments here:

Your comments will be displayed after verification.