ok so the question is: "How many five digit natural numbers contain the digits $0$ and $3$ (each on of them) at least once.
So I think I have an answer, but not sure if it's right:
I take all the possibilities for forming a five-digit number $9\times10^4$ and subtracting whole numbers that not contain $0$ or $3\times8^5$
so my answer is : $9\times10^4-8^5$.
Is it right?