Question - An international business operation manager is considering buying a smartphone and phone service plan. There are three service plans to choose from, all of which involve a weekly charge of $25. Plan A has a cost of $0.35 a minute for daytime calls and $0.10 a minute for evening/night/weekend calls. Plan B has a charge of $0.45 a minute for day time calls and a charge of $0.05 a minute for evening/night/weekend calls. Plan C has a flat rate of $75 with 200 minutes of calls allowed per week and a cost of $0.30 per minutes beyond that, day or evening/night/weekend.
a) Determine the total fee under each plan for this case: 150 minutes of daytime calls and 50 minutes of evening/night/weekend calls in a week.
b) If the manager plans to use the service for only daytime calls, over what range of call minutes will each plan be optimal.
c) Suppose that the manager expects both daytime and evening/night/weekend calls. At what percentage of calls minutes for daytime calls would she be indifferent between plans A and B?
Please show answer with full work so I can understand please! Thanks.