Lucy can choose Plan A or Plan B for her long distance charges. For each plan, cost (in dollars) depends on minutes used (per month) as shown below. Plan A Cost (in dollars) Minutes used (per month) (a) If Lucy makes 50 minutes of long distance calls for the month, which plan costs less? OPlan A O Plan B How much less does it cost than the other plan? $ (b) For what number of long distance minutes do the two plans cost the same? If the time spent on long distance calls is more than this amount, which plan costs less? O Plan A JPlan B