11. If the system of inequalities $\left\{\begin{array}{l}x-1>0, \\ x-a<0\end{array}\right.$ has no solution, then the range of values for $a$ is $\qquad$
$$
\text { II, 11. } a \leqslant 1 \text {. }
$$

Solve the system of inequalities $\left\{\begin{array}{l}x-1>0, \\ x-a1, \\ x<a .\end{array}\right.$
Since the original system of inequalities has no solution, it must be that $a \leqslant 1$