How many possible combinations are there on a 4 digit lock using numbers 0-9, if duplicate numbers are not allowed?

Question

asked May 15, 2017 210k views

1 Answer

Jason Molenda · Answer 1 · 2017-05-21T21:59:13+0000

0,1,2,3,4,5,6,7,8,9 = 10 possible numbers
No repeats so every time you use one subtract it from the amount of numbers you have.
10x9x8x7=5,040