Suppose that in a senior college class of ​students, it is found that ​smoke, drink alcoholic​ beverages, eat between​ meals, smoke and drink alcoholic​ beverages, eat between meals and drink alcoholic​ beverages, smoke and eat between​ meals, and engage in all three of these bad health practices. If a member of this senior class is selected at​ random, find the probability that the student​ (a) smokes but does not drink alcoholic​ beverages; (b) eats between meals and drinks alcoholic beverages but does not​ smoke; (c) neither smokes nor eats between meals.