q1: Every week, Sarah is paid $30 per hour for the first 30 hours she works, and $60 per hour for each hour she works after the first 30 hours. How many hours would Sarah have to work in one week to earn an average ( arithmetic mean) of $50 per hour that week?

q2: A and B are graphical representations of normally distributed random variables X and Y, respectively, with relative positions, shapes, and sizes as shown. Which of the following statements about X and Y are true and which one is false ? Explain your answer . B a. Y has a smaller standard deviation than X. b The probability that Y falls within 2 standard deviations of its mean is greater than the probability that X falls within 2 standard deviations of its mean. c Y has a smaller mean than X.

q3: The probability that Sarah will win the Booker prize is 0.5, and the probability that Nail will win the Booker prize is 0.4. There is only one Booker prize to win. What is the probability that at least one of them wins the prize ?