33. Find the number of even digits in the product of the two 10 -digit numbers
$$
2222222222 \times 9999999999 .
$$
33 Ans: 10.
$$
\begin{aligned}
2222222222 \times\left(10^{10}-1\right) & =22222222220000000000-2222222222 \\
& =222222222177777777778
\end{aligned}
$$