Question

Pratap puri rowed 10 miles down a river in 2 ​hours, but the return trip took him 2 and one half hours. Find the rate pratap can row in still water and find the rate of the current.

Answer 1

Answer:

Rate of Pratap in still water is 4.5 miles/hour and rate of current is 0.5 miles/hour.

Step-by-step explanation:

Pratap Puri rowed 10 miles down a river in 2 ​hours, but the return trip took him 2.5 hours.

We know that, $Speed = \frac{Distance}{Time}$

So, the speed of Pratap with the current will be:  $(\frac{10}{2})miles/hour = 5$ miles/hour

and the speed of Pratap against the current will be:  $(\frac{10}{2.5})miles/hour = 4$ miles/hour.

Suppose, the rate of Pratap in still water is $x$ and the rate of current is $y$.

So, the equations will be........

$x+y= 5 .............................. (1)\\ \\ x-y=4 .............................. (2)$

Adding equation (1) and (2) , we will get......

$2x=9\\ \\ x=\frac{9}{2}= 4.5$

Now, plugging this $x=4.5$ into equation (1), we will get.....

$4.5+y=5\\ \\ y=5-4.5 =0.5$

Thus, Pratap can row at 4.5 miles per hour in still water and the rate of the current is 0.5 miles/hour.