Question

A policeman is chasing a criminal across a rooftop at 10 m/s. He decides to jump to the next building which is 2 meters across from the original and 2.5 meters lower. How long (in seconds) will it take him to cross between buildings?

Answer 1

At 10 m/s, it will take
  (2 m)/(10 m/s) = 0.2 s
to bridge the gap.

_____
However, it will take an additional 0.514 seconds (0.714 s total) for the policeman to land on the building below. The answer depends on the meaning of the question.