Last winter, someone made two snowballs, one of which had twice as big a diameter as the other one. Unfortunately, the weather did not cooperate, and the snowballs started to melt soon. The melting only took place at the surface of the balls, so the speed with which the balls melted was proportional to the surface of the (remainder of the) balls.

The question: How much was left of the small snowball, when half of the volume of the large snowball had melted?

The answer: Click here!