For each of the following scenarios, state whether there is or is not a contract, and why:

1. Bob and Mary were talking at a bar on Thursday night. Bob wrote the following on coaster and handed it to Mary:

I promise to pay you $1,000 to dance with man at the bar in the Gray Shirt

Mary read the coaster, signed it, and danced with the man in the gray shirt.

2. Mr. Wilson said to 18 year old Dennis:

Take care of my yard and mow it while I am away on vacation, and I will pay you fifty dollars upon my return.

Dennis mowed the yard on Saturday. On Sunday. The temperature set a new high, and Mr. Wilsons grass was burned due to a lack of water. Dennis tried to collect the $50 from Mr. Wilson.

3. Donald went to a retail shop selling sports trading cards. He said to the store owner Id give anything for valuable card of my favorite player, Nolan Ryan. The store owner gave Donald a Nolan Ryan card worth $50, and told Donald to scrub the floor and clean the bathroom. Donald refused and left the store with the Nolan Ryan Card.