Each question below is followed by three statements I,II and III. You have to determine whether the data given in the statement/statements is sufficient for answering the question. You should use the data and your knowledge of Mathematics to choose the best possible answer.
What is the speed of boat in still water?
I. The boat can cover 25 km downstream distance in 5 hours.
II. Speed of the stream is two-third of the speed of boat in still water.
III. The boat can cover 25 km upstream distance in 10 hours.

Options

A. I and III together
B. Only II
C. I and II together
D. I and either II or III