The slope of a line passing through two points is given by the formula $\frac{y_2 - y_1}{x_2 - x_1}$. Substituting the points $(2,5)$ and $(4,11)$ into the formula gives $\frac{11-5}{4-2} = \frac{6}{2} = 3$. Therefore, the slope of the line is 3.