Much easier to work with its complement. (Hint: when it says AT LEAST in probability, you should much rather work with the complementary pairing)
[tex]\text{Pr(at least two 2's) = 1 - Pr(1 2) - Pr(no 2's)}[/tex]
[tex]\text{Pr(1 2's)} = \binom{13}{1}\left( \frac{1}{6}^{1} \cdot \frac{5}{6}^{12}\right)[/tex]
[tex]\text{Pr(no 2's)} = \left(\frac{5}{6}\right)^{13}[/tex]
[tex]\therefore \text{Pr(at least two 2's)} = 0.663530036... \text{ (by calculator work)}[/tex]
