saw an interesting problem last night
if there are 25 ducks, and you can only race 5 ducks at a time, how many races do you need to see which 3 ducks are the fastest?
each race will only tell you their relative speeds (ie ducky 3 was the slowest, but ducky 4 was the second fastest)
this is more proofs than math, but i guess they're pretty similar
iirc you dont start doing these kinds of proofs until you're in college, unless you take a class on it in high school
i'm gonna venture a guess and say 10 or 11. i need to work this out a bit more before i can be sure