Green, the designing engineer from the M&P' toy manufacturing company is designing a 'ball-in-a-ball-in-a-ball · · ·' toy where, for child safety reasons, the largest ball has a diameter of 12 cm and the smallest ball must be at least 5 cm in diameter. Each ball splits in half to expose the next ball. The ball inside another ball is 10 percent smaller than the ball it came from. Also, 85 percent of each ball's volume is air space in order to provide space for the next-smaller ball. What is the largest number of balls in this toy? How much plastic is required to build this toy?