A store manager gathers some demographic information from the store's customers. The following chart summarizes the age-related information they collected: Age Number of Customers 60 55 One customer is chosen at random for a prize giveaway. (Round answers to 4 decimal places.) a. What is the probability that the customer is at least 20 but no older than 49? | 0 X b. What is the probability that the customer is either older than 60 or younger than 40? 0 X c. What is the probability that the customer is at least 60? 0 X