Asixteen sided number cube has the numbers 1 through 16 on each face. each face is equally likely to show after a roll. what is the probability that you will roll an even number or an odd prime number? round to the nearest thousandth

The possibilities of an even number are  2,  4,  6,  8,  10,  12,  14, and  16 .

The possibilities of an odd prime are  3,  5,  7,  11,  and  13.

8 even numbers + 5 odd primes  =  13 possibilities of success

                                                 out of 16 total possible outcomes.

Probability of success  =  13/16 =   0.8125  =  81.25% .

Rounded to the nearest thousandth, it's 0.813 .

X> -2 is the simplified version.