P. 4265. A 200 m-long car convoy is travelling at a speed of 10 m/s. From the end of the convoy a motorbike starts to move to the front of the convoy at a speed of 20 m/s.
a) How long does it take to reach the front of the convoy?
b) How long does it take to go back?
Deadline expired on 11 October 2010.