I argued this one with my Physics teacher...told him his statement of the problem was wrong....in the real world, the 'other side of the coliseum' is an arbitrary limit on the distance travelled...he was having none of it..and basically said the example illustrates the point he was trying to get across about calculus...he tried to pull the same {censored} about the tortoise never being able to catch the hare...pfft. I agree with you - what if the coliseum were only 1/2 as big? Then the first assumption that you first have to cross the first half, would put you all the way across!! I realize I'm arguing both sides of MY argument............