6. For two numbers $a$ and $b$, define a new operation, $a \Delta b=3 \times a+2 \times b, a \nabla b=2 \times a+3 \times b$, then $3 \Delta(2 \nabla 1)=$ $\qquad$
Analysis: The key point is to define new operations.
It is a very simple question, just calculate in order directly.
$$
\begin{array}{l}
3 \Delta(2 \nabla 1) \\
=3 \Delta(2 \times 2+3 \times 1) \\
=3 \Delta 7=3 \times 3+2 \times 7=23
\end{array}
$$