Sam supplies gelato for Daisys business.

• On Monday, Daisy orders 40kg of gelato to be delivered on Friday. Sam replies, I can do that for $100. Daisy says Okay, great, Ill transfer the money now. Daisy transfers $100.
• On Tuesday Sam tells Daisy that he only has 30kg of gelato in stock. Daisy says that is disappointing, can you deliver it on Thursday instead, and refund $25?. Sam agrees and refunds Daisy $25.
• On Thursday Sam delivers 15kg of gelato to Daisy.
• On Friday Daisy demands that Sam deliver 5kg of gelato for free.

Advise Sam. Include in your answer whether there is a valid contract(s), what the terms of that contract or contracts are, and whether Sam has any outstanding contractual obligations to Daisy. (Consider the material in the Week 4 lecture and readings to prepare your answer).