Two distinct number cubes, one red and one blue, are rolled together. Each number cube has sides numbered 1 through 6.

The sum can be $4,6,8,12$. Some casework:

 

4 can be written as $2+2, 1+3, 3+1$

6 can be written as $1+5, 5+1, 4+2, 2+4, 3+3$

8 can be written as $2+6, 6+2, 3+5, 5+3, 4+4$

12 can be written as $6+6$

 

The total number of ways is $14$. There are $36$ possibilities. The answer is $\frac{14}{36}=\frac{7}{18}$.

$\frac{\lfloor \frac{36}{4} \rfloor + \lfloor \frac{36}{6} \rfloor - \lfloor \frac{36}{24}\rfloor}{36}$

$\frac{14}{36}$

$\frac{7}{18}$