AMO 2027 Grades 8-9 SET 9 - Self-study Question 14

The numbers $a_1,a_2,a_3$ and $a_4$ are drawn one at a time from the set $\{0,1,2,\ldots,9\}$. If these four numbers are drawn with replacement, what is the probability that $a_1a_4-a_2a_3$ is an even number?