One insurance plan costs $100 a month and has a $50 copayment for all services. Another insurance plan costs $50 a month and requires patients to pay a 15% coinsurance. A consumer is trying to decide which plan to purchase.

Which plan would the consumer select with an anticipated $200 per month in medical bills? What about $600 per month in medical bills? Set up an equation to determine the monthly amount of medical expenses at which the consumer would be indifferent between the two plans.