Question

A man can swim downstream at 10 km/hr and upstream at 5 km/hr. what is the speed of the current?

Answer 1

Let man's speed be x and the current's speed be y
Therefore,
Upstream: x - y = 5.....(i)
Downstream: x + y =10.....(ii)

Simplifying, we get x = 7.5 kmph and y = 2.5 kmph

Answer 2

Answer:

speed of current = 2.5 km/hr

Step-by-step explanation:

Let the speed of the man in still water is x and the speed of current is y.

It has been given that

speed of man in downstream is 10 km/hr. Thus, we have

speed of man + speed of current = 10

x + y = 10...(i)

Now, speed of man in upstream is 5 km/hr. Thus, we have

speed of man - speed of current = 5

x - y = 5...(ii)

Add (i) and (ii)

2x = 15

x = 7.5

Plugging this value in (i)

7.5 + y = 10

y = 10 - 7.5

y = 2.5

Therefore, we have

speed of current = 2.5 km/hr