If you took 800mg of aspirin tablet at 12:00pm and another 800mg tablet at 2pm, how many milligrams of aspirin are still in your system at 3pm? Aspirin has a t1/2 of 1 hour.

Don't you dare put a link. I have a very specific set of skills >.>
(Chemistry is unfortunately not one of them though, so please help me ^-^)