Question

Can you explain why it's always 1 ??

Pick any number.
If that number is even, divide it by 2.
If it's odd, multiply it by 3 and add 1.
Now repeat the process with your new number.
If you keep going, you'll eventually end up at 1.
Every time.!

Answer 1

The thing is, they've never been able to prove that, lol. (:

there is no special number out there that never leads to 1. It's possible that there's some really big number that goes to infinity instead, or maybe a number that gets stuck in a loop and never reaches 1. But no one has ever been able to prove that for certain.