In a simultaneous throw of two dice, we have $n(\mathrm{S})=$ $(6 \times 6)=36$. Let $E=$ event of getting two numbers whose product is even. Then, $E=\{(1,2),(1,4),(1,6),(2,1),(2,2),(2,3)$, (2, 4), (2, 5), (2, 6), (3, 2), (3, 4), (3, 6), (4, 1), (4, 2), (4, 3), (4, 4), (4, 5), (4, 6), (5, 2), (5, 4), (5, 6), (6, 1), (6, 2), (6, 3), (6, 4), (6, 5), (6, 6)\}. $$\begin{array}{ll} \therefore & n(E)=27 . \\ \therefore & P(E)=\frac{n(E)}{n(S)}=\frac{27}{36}=\frac{3}{4} . \end{array}$$