6. There are two specifications of steel bars, A and B, and C. It is known that 2 bars of type A, 1 bar of type B, and 3 bars of type C are a total of 23 meters long; 1 bar of type A, 4 bars of type B, and 5 bars of type C are a total of 36 meters long. How long are 1 bar of type A, 2 bars of type B, and 3 bars of type C?
6. Slightly explained: Let the lengths of copper strips of specifications A, B, and C be $x, y, z$ meters, respectively, then
$$
\left\{\begin{array}{l}
2 x+y+3 z=23, \\
x+4 y+5 z=36
\end{array}\right.
$$

From (1) - (2) $\times 2$, we get $y=7-z$.
Substituting $y$ into (2), we get $x=8-z$.
Substituting $x, y$ into $x+2 y+3 z=8-z+14-2 z+3 z=22$ (meters).