Question

How many $3$-digit even numbers are formed using the digits $0,1,2,....,9,$ if the repetition of digits is not allowed?

Answer 1

$\begin{array}{c}0,to,9\Rightarrow 10nos\\ 8\times 9=72\\ 8\times 8\times 4=256\\ 72+256=328\end{array}$