Xavier Aptitude Test 2021 Paper

Question : 9 of 100

Marks: +1, -0

Swati can row a boat on still water at a speed of 5 km/hr. However, on a given river, it takes her 1 hour more to row the boat 12 km upstream than downstream. One day, Swati rows the boat on this river from $\X$ to $|Y$ , which is $\N$ km upstream from $\X$ . Then she rows back to $\X$ immediately. If she takes at least 2 hours to complete this round trip, what is the minimum possible value of $\N$ ?

Validate

Solution:

Let the speed of the stream be

x

12/{5-x} = 12/{5+x} +1

The value of

x

satisfying the above equation is

1

Now

\N/{5+1} + \N/{5-1}≥ 2

{2\N + 3\N}/12 ≥ 2

⇒\N ≥ 4.8

Go to Question:

Prev Question

Next Question