TeX source:

P(A|B) = \dfrac{P(A \text{ AND }B)}{P(B)}=\dfrac{\dfrac{\text{(the number of outcomes that are 2 or 3 and even in S)}}{6}}{\dfrac{\text{(the number of outcomes that are even in S)}}{6}}=\dfrac{\dfrac{1}{6}}{\dfrac{3}{6}}=\dfrac{1}{3}