#### Answer

$\frac{1}{36}$

#### Work Step by Step

The events are independent.
A number cube has 6 sides(1,2,3,4,5,6):
P(6)=$\frac{1}{6}$
A number cube has 6 sides (1,2,3,4,5,6)
P(3)=$\frac{1}{6}$
P(6 then 3)=P(6) $\times$ P(3)
P(6 then 3)=$\frac{1}{6}$ $\times$ $\frac{1}{6}$
P(6 then 3 )=$\frac{1}{36}$