Miles is three years old and his grandparents have given him money to spend at the toy store as a birthday present. Miles' number one favorite thing to play with is building blocks. Assume that Miles' utility will increase by 100 units if he purchases a new set of building blocks and and it will cost him $50. His second favorite thing to play with is fire trucks. Fire trucks cost $20 and each new fire truck improves Miles' utility by 80 units. His third favorite toy is trains. Trains improve his utility by 15 units and cost $5 each. Required:
a. If Miles buys only one toy, which should he buy to maximize his utility?
b. In general, which condition below indicates that a consumer is maximizing his or her utility regarding spending on two goods?

Areal 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 $20. plan a has a cost of $.42 a minute for daytime calls and $.17 a minute for evening calls. plan b has a charge of $.52 a minute for daytime calls and $.15 a minute for evening calls. plan c has a flat rate of $80 with 275 minutes of calls allowed per month and a charge of $.38 per minute beyond that, day or evening.a. determine the total charge under each plan for this case: 150 minutes of day calls and 70 minutes of evening calls in a month. (do not round intermediate calculations. round your answer to 2 decimal places. omit the "$" 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?