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.

Aanchal said:   5 years ago
Su = ?
Sd = 15km/hr,
Sd = x+ y.
x+ y = 15km/hr,
x + 2.5 = 15km/hr,
x = 12.5.

x = speed of man in still water.
Sd = x -y.
15- 2.5 = 10km/hr.
(1)

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.

Kush said:   1 decade ago
hi ! @Vijaya.

In question, it will be already provided the keyword like upstream or downstream and With stream or Against Stream.

Praveen said:   6 years ago
MS with CS = 15.
CS = 2.5,
MS = 15-2.5= 12.5.

Against means Opp direction so it is Upstream For this MS - CS so 12.5 -2.5 = 10.

Mani said:   1 decade ago
Here they did not mention that is/clearly not questioned that this is a boad and stream problem.

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.

HARI said:   7 years ago
Speed in current =15,
Current speed =2.5,
Upstream =15-2.5=12.5,
Downstream =15+2.5=17.5.

Pinky said:   1 decade ago
Please explain me, why man's rate subtract form the current,

I'm not understanding.

Rucha said:   10 years ago
Can anybody explain me the meaning of question clearly. It's to confusing for me.


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