Keith can choose Plan A or Plan B for his long distance charges. For each plan, cost (in dollars) depends on minutes used (per month) as shown below. .... .....i.... .Plan A ..... Plan B 28 Cost 24 (in dollars) 100 150 200 250 300 350 400 450 Minutes used (per month) (a) If Keith makes 400 minutes of long distance calls for the month, which plan costs more? X O Plan A O Plan B How much more 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 less than this amount, which plan costs less? O Plan A O Plan B