A real estate agent is considering changing her cell phone plan

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 $29. Plan A has a cost of $0.45 a minute for daytime calls and $0.29 a minute for evening calls. Plan B has a charge of $0.51 a minute for daytime calls and $0.17 a minute for evening calls. Plan C has a flat rate of $95 with 253 minutes of calls allowed per month and a charge of $.40 per minute beyond that, day or evening.