Final answer:
Only the scenario involving Mr. Ng's promise under seal to the Canadian Cancer Society (A) represents a binding agreement given the details provided, with the assumption that a seal is considered as an exception to the requirement of consideration in the relevant legal system. The extra payment to the programmer for on-time completion (E) also likely constitutes a binding agreement due to consideration and modification of terms which were accepted.
Step-by-step explanation:
Assuming all other requirements for a valid contract are present, we need to assess which of the mentioned scenarios would result in a binding agreement. Generally, a valid contract requires an offer, acceptance, consideration (something of value exchanged), and the intention to create legal relations.
A) In the case of Mr. Ng's promise to the Canadian Cancer society, this would be considered a binding agreement if the promise is made under seal, which is a formal legal expression of the promise, even without consideration, especially in some legal systems.
B) John's promise of $50 to Jim for returning a lost computer disk is not enforceable because there is no consideration from Jim; the act of returning the disk was not done with the intention of creating a legal obligation.
C) Len offering to sell a snowboard to Chuck for $400, and Chuck saying no is simply a rejected offer and does not create a binding agreement.
D) Joe offering to pay the florist to put flowers on a grave and the florist agreeing only for 10 weeks does not constitute a binding agreement on the original terms offered. It can be seen as a counter-offer which Joe can accept or reject.
E) The owner of the company offering additional payment to a programmer for completing work on time constitutes a binding agreement as there is consideration and an acceptance of the modified terms.