For how many days does a typical mayfly live?

Mayflies are known for their extremely brief adult life cycle, which is one of the shortest among all insects. The adult mayfly stage, also referred to as the subimago or imago stage, typically lasts only about one day. This brief lifespan is primarily dedicated to reproduction, as adults emerge from water, mate, and then quickly die. This ephemeral life cycle has led to the popular belief that mayflies live for just one day, which is accurately reflected in the choice that states a lifespan of 1 day. While it's true that some species may live slightly longer—potentially up to a week in their adult form—the most recognized and commonly accepted answer highlights their characteristic brevity, making the answer of one day the fitting choice in this context.