Final answer:
The mailbox rule applies to all of these: real estate contracts, personal service contracts, and interstate contracts. According to this legal principle, an acceptance of an offer is effective when it is sent or communicated through the mail, rather than when it is received by the offeror.
Step-by-step explanation:
The mailbox rule applies to all of these: real estate contracts, personal service contracts, and interstate contracts.
The mailbox rule is a legal principle that determines the time at which a contract is formed when it is sent through the mail. According to this rule, an acceptance of an offer is effective when it is sent or communicated through the mail, rather than when it is received by the offeror.
For example, if a person mails an acceptance letter for a real estate contract to the seller, even if the seller has not yet received the letter, the contract is considered formed at the moment the acceptance was mailed.