Question

A combination lock has a password that is three numbers between 0 and 99. assuming the same number can't be used more than once in a password, how many potential passwords are there?

Answer 1

Oooooo, permutations!
The answer is simple. The first number is represented by 100. 100 possible solutions.
But the next number is 99. We have removed one number from the set, since numbers cannot repeat. The final number is 98.
Multiply together
100*99*98= 970,200 possible solutions.
If you want to open this lock, you would need a supercomputer!