I'm just studying for finals here and wanted some confirmation that I'm doing things right.
So if we have 5-digit decimal numbers, there are:
- $10^5 - 9*8*7*6*5$ numbers with no $0$,
- $10^5 - 9*8*7*6*5$ numbers with no $1$, and
- $10^5-2(9*8*7*6*5)+8*7*6*5*4$ numbers with no $0$ or $1$.
Am I correct? Your help is so greatly appreciated.