How many hours is 1 pm to 9 pm?

Answer 1

Imagine all the different times on a number line, starting at midnight (00:00 AM) and ending at just before midnight (something like 11:59 PM).

Then, you can look at how many times you can move along this line in 1 hour steps.

Start at 1 PM, then move along one step to 2PM, another to 3PM and so on until you reach 9 PM.

You would have moved 9 - 1 = 8 hours.