Having only digits $1,2,3$. How many $10$-digit numbers can you make with these digits such that you do not use 1 at all? ($2^{10}$?)
How many $10$-digit numbers can you make with these digits provided you use $1$ twice? ($2^8$?)
Having only digits $1,2,3$. How many $10$-digit numbers can you make with these digits such that you do not use 1 at all? ($2^{10}$?)
How many $10$-digit numbers can you make with these digits provided you use $1$ twice? ($2^8$?)