Question

A person covers 32km .downstream is 240 minutes and same person covers 48 km .upstream in 1440 minutes .find the rate of current

Answer 1

Answer:

Speed of the current is 3 km/hr.

Step-by-step explanation:

Let x km/hr be the speed of the current

    y km/hr be the speed of the person

Given: Time 240 minutes = 4 hr   and 1440 minutes = 24 hr

Speed of the Downstream = x + y

Speed of the Upstream = y - x

Using Speed Distance formula,

we get,

x + y = 32/4

x + y = 8 ..................(1)

y - x = 48/24

y - x = 2 .....................(2)

Using Elimination method,

Add eqn(1) and (2), we get

2y = 10

y = 5

putting this value in eqn (1),

x = 8 - 5 = 3

Therefore, Speed of the current is 3 km/hr.

Answer 2

Answer:

3

Step-by-step explanation:

Let speed of the person be x and speed of the current be y.

Now in downstream total speed = speed of current + speed of person

Distance travelled is 32 km and time taken is 240 / 60 = 4 hours.

Now total speed = x + y = distance travelled / time taken = 32/4 = 8 km/hr

So we have x + y = 8----------------1

In upstream we have total speed = x – y

So 60 min = 1 hr

1440 min = 1440 / 60 = 24 hrs

Now total speed = 48/24 = 2 km/hr  

X – y = 2------------------2

So from 1 and 2 we get

X + y = 8

X – y = 2

2 x = 10

X = 5, y = 3

Now speed of current is y = 3 km/hr