Question

What is the speed of the boat in still water?
I. The boat covers a distance of 48 kms in 6 hours while running upstream.
II. The boat covers the same distance in 4 hours while running downstream.

• A. I alone sufficient while II alone not sufficient to answer
• B. II alone sufficient while I alone not sufficient to answer
• C. Either I or II alone sufficient to answer
• D. Both I and II are not sufficient to answer
• E. Both I and II are necessary to answer

Answer 1

Answer: (E)

Both I and II are necessary to answer

I. Speed upstream $=\frac{48}{6}km/hr=8km/hr$
II. Speed upstream $=\frac{48}{4}km/hr=12km/hr$
Speed of the boat $=\frac{1}{2}(8+2)km/hr=10km/hr$
Thus, I and II together give the answer.
$\therefore$ Correct answer is (E).