Vector Algebra

Let $\vec{a}$ and $\vec{b}$ be two vectors such that $|\vec{a}+\vec{b}|=15$ and

\(\vec{a} \times(3 \hat{i}-4 \hat{j}+5 \hat{k})=(3 \hat{i}-4 \hat{j}+5 \hat{k}) \times \vec{b}\)

What is the value of $|(\vec{a}+\vec{b}) \cdot(2 \hat{i}+3 \hat{j}+\hat{k})|$ ?