Explain, in detail, an "enforceable contract." (What is required for an agreement to be a binding contract? - Chapter 9)

Provide an example of an enforceablecontract and explain "why" it is enforceable.

Explain, in detail, an "unenforceable contract.

Provide an example of an unenforceable contract and explain "why" it is unenforceable.

Explain, in detail, a "non-contractual promise."

Provide an example of a non-contractual promise that is "enforceable," and explain "why" it is enforceable.

Provide an example of a non-contractual promise that is "unenforceable," and explain "why" it is unenforceable.