Determine if the following situations create a valid and enforceable contract with respect to the questions of consideration. Give a short reason for your answer.

Tom: Ill pick up your car from the garage and deliver those papers to your client, Mr. Big Shot. Ted: Thanks, that will really help me out. Tom does not pick up the car.

Agnes finds Junes gold necklace in the washroom at work and returns it to her. June: Thanks so much! Ill give you $50 when I get paid next week. Next Thursday, Agnes does not receive the $50.

Andrew agrees to sell his antique chair to Peter for $300. Peter walks away smiling, knowing that the chair is worth at least twice as much.

Alice agreed to give Jim bass guitar lessons for four months, one half-hour lesson per week at the rate of $25 per lesson. After five lessons, Jim was so happy with his musical progress that he offered to pay Alice $30 per lesson. Alice immediately accepted.