Question: 1. You are given 10 white and 10 black balls and two boxes. You are told that your instructor will draw a ball from one of the two boxes. If it is white, you pass the exam. If it is black, you fail. How should you arrange the balls in the boxes to maximize your chance of passing?
2. An instructor wishes to "grade on the curve." The students; scores seem to be normally distributed with mean 70 and standard deviation 8. If the instructor wishes to give 20 percent As, what should be the dividing line between an A grade and a B grade?