" He believed the umbrella was his own and had no intent to deprive anyone else of property. 4. A reward poster for a lost dog is a unilateral contract. "I will pay you $1,000 for the return of my dog Zorro, in healthy and alive condition." The offer is the $1,000. The acceptance is the return of the dog, and a unilateral contract is only accepted by performance. A bilateral contract is a contract that is fulfilled by promises. The offer would be, "I will pay you $1,000 to purchase a puppy from your dog Zorro's litter." The acceptance is made with a promise to sell me that puppy. Now both parties are mutually obligated; I am obligated to pay the money for the puppy, while the seller is obligated to tender the puppy.

5. Tom and John enter into the following contract when John's daughter is born.

John promises to have Tom marry his daughter when she reaches the age of 18 in exchange for Tom lending John $50,000 to start a business. The contract...

The contract is executor because it has not been fully performed. The contract is bilateral because both parties have obligations under the contract.
6. No, there is no valid contract for the sale of the laptop. Farrah did not offer to sell the laptop for $400, but was merely discussing selling her laptop. An offer has to be specific in order to be enforceable. Because there was no valid offer, there can be no valid acceptance. Even if Farrah's $300 figure was considered an offer, David's offer to pay $400 would have been a counter-offer, not an acceptance.

7. No, there is no valid contract between Farrah and David for the sale of Farrah's daughter. While there was a specific offer ($1,000), and David agreed to Farrah's terms, the contract is void. Illegal contracts are void, not voidable, and…