Yeah the answer is 1620

Sum to infinity is 900, however the question wants total distance travelled

The ball goes up and down for each term, 900 x 2 = 1800

1800 - 180 (the ball does not go back to the starting point) = 1620

PS: KhorJyang here, accidentally used bro's acc!

This post has been edited by Party2DMax: Nov 7 2008, 12:12 AM