The paradox holds in an infinitely dividable setting. Take the series of numbers where the next number equals the previous one divided by 2: {1, 1/2, 1/4, 1/8, 1/16…}. If you take the sum of this infinite series (there is always a larger factor of two to divide by) you are going to get a finite result (namely 2, in this instance). So for the real life example, while there is always another ‘half’ of the distance to be travelled, the time it takes to do so is also halved with every iteration.