Let \( X \) be a random variable with the probability density function \[ f(x) = \begin{cases} \dfrac{\alpha^{p}}{\Gamma(p)} e^{-\alpha x} x^{p-1}, & x \geq 0, \, \alpha > 0, \, p > 0, \\ 0, & \text{otherwise}. \end{cases} \] If \( E(X) = 20 \) and \( \text{Var}(X) = 10 \), then \( (\alpha, p) \) is