Quantitative Aptitude Ques 420

Question: A man can row 9 km/h in still water. It takes him twice as long to row up as to row down the river. Find the speed of stream.

Options:

A) 3 km/h

B) 4 km/h

C) 5 km/h

D) 6 km/h

E) None of the above

Show Answer

Answer:

Correct Answer: A

Solution:

  • Let x be the speed of stream, $ 9+x=2,(9-x) $
    $ \Rightarrow , $ $ 9+x=18-2x $

$ \Rightarrow $ $ 3x=18-9=9 $
$ \Rightarrow , $ $ x=3,km/h $