An increasing number of consumers believe they have to look out for themselves in the marketplace. According to a survey conducted by the Yankelovich Partners for USA WEEKEND magazine, 60% of all consumers have called an information line for a product. Suppose a random sample of 20 consumers is contacted and interviewed about their buying habits.

a. What is the probability that 11 or more of these consumers have called an information line for a product?

b. What is the probability that more than 15 of these consumers have called an information line for a product?

Please full step-by-step procedures and explanations including the formulas and calculating process. Will rate helpful.