How many strings of 4 decimal digit do not contain the same digit twice?

Question

asked Sep 8, 2018 43.5k views

1 Answer

Azi · Answer 1 · 2018-09-12T16:27:30+0000

9*9*8*7

You can choose 9 digits for the first digit, 9 Fót the second (because IT can be 0) and 8 Fót the third etc.. hope this helps