A real estate agent is considering changing her cell phone plan. There are three plans to choose from, all of which involve a monthly service charge of exist20. Plan A has a cost of exist.42 a minute for daytime calls and exist.17 a minute for evening calls. Plan B has a charge of exist.52 a minute for daytime calls and exist.15 a minute for evening calls. Plan C has a flat rate of exist80 with 275 minutes of calls allowed per month and a charge of exist.38 per minute beyond that, day or evening. Determine the total charge under each plan for this case: 150 minutes of day calls and 70 minutes of evening calls in a month. (Do not round intermediate calculations. Round your answer to 2 decimal places. Omit the "exist" sign in your response.) c. If the agent will use the service for daytime calls, over what range of call minutes will each plan be optimal? (Round each answer to the nearest whole number. Include the indifference point itself in each answer.) d. Suppose that the agent expects both daytime and evening calls. At what point (i.e., percentage of total call minutes used for daytime calls) would she be indifferent between plans A and B? (Do not round intermediate calculations. Enter your answer as a percentage rounded to 2 decimal places. Omit the "%" sign in your response.)