#### Answer

$\frac{5}{6}$

#### Work Step by Step

Use P(not 3)=$\frac{numberoffavorableoutcomes}{numberofpossibleoutcomes}$.
There are 6 possible outcomes:1,2,3,4,5 and 6. There are 5 favorable outcomes: 1,2,4,5 and 6.Plug in the number of outcomes:
P(not 3)=$\frac{numberoffavorableoutcomes}{numberofpossibleoutcomes}$.
P(not 3)=$\frac{5}{6}$