A snooze button typically delays an alarm by how many minutes?

You've probably wondered why snooze buttons only give another nine minutes in dreamland. Nine minutes seems like an arbitrary timeframe. Why not make it an even 10? There's a good explanation for it. By the time the snooze feature was added in the 1950s, the innards of alarm clocks had long been standardized. This meant that the teeth on the snooze gear had to mesh with the existing gear configuration, leaving engineers with a single choice: They could set the snooze for either a little more than nine minutes or a little more than 10 minutes. But because early reports indicated that 10 minutes was too long, allowing people to fall back into a "deep" sleep, clock makers decided on the nine-minute gear.

Source: Mental Floss