An exercise club offers three payment plans for aerobics classes. Plan A charges $6 per class plus a one-time membership fee of $35. Plan B charges $5 per class plus a one-time membership fee of $50. Plan C offers unlimited aerobic classes for a one-time membership fee of $149. Part A: Write and solve an inequality to find how many classes you would have to attend for Plan A to be a better value than Plan B. Part B: Write and solve an inequality to find how many classes you would have to attend for Plan A to be a better value than Plan C. Part C: The club reduces the cost of Plan C to $100. If you attend 15 classes, which plan is now the best value? Explain your reasoning.