A question is given, followed by three statements labelled I, II and
III. Identify which of the statements is are sufficient to answer the question. Question: What is the time (in second) taken by A to run the race? Statements:
I. A beats B by 30 seconds and B beats C by 60 seconds.
II. A beats C by 90 seconds.
III. B's speed is the average of A's speed and C's speed.