\[P = P_{4}(3) + P_{4}(4) =\]
\[= \frac{4 \bullet 3!}{3! \bullet 1} \bullet \frac{5}{6^{4}} + \frac{1}{6^{4}} = \frac{20}{6^{4}} + \frac{1}{6^{4}} = \frac{21}{6^{4}} =\]
\[= \frac{21}{1296} = \frac{7}{432}.\]
\[Ответ:\ \ \frac{7}{432}.\]