Official solution
\[{}^5{C_0} \times {3^5} = 243\]
\[{}^5{C_2} \times {2^2} \times {3^3} = 1080\]
\[{}^5{C_4} \times {2^4}\,.\,3 = 240\]
\[\therefore\] required probability
\[ = {{243 + 1080 + 240} \over {6 \times 6 \times 6 \times 6 \times 6}} = {{521} \over {2592}}\]