Find total probability for Binomial pdfs

Question

1. In a two-class classification problem with a single feature $X$ the pdfs are $\operatorname{Bin}(n,p)$ with $n=10$ for both classes and $p$-values $0.6$ and $0.4$ respectively. Find the decision boundary point for MAP classifier. Assume the two classes have equal prior probability.
2. What is the total probability of $X = x$?

I am struggling to find out the answer for no 2. Can anyone help me out with some hints?

Answer 1

Straightforward:

$P(X=x)=\frac{1}{2}\binom{10}{k}(0.6^k\times0.4^{10-k}+0.4^k\times0.6^{10-k})$