Question

Using a 12 sided number cube, what is the probability that you will roll an even number or an odd prime number? The number 1 isn’t an odd prime. Give answer as a decimal rounded to three decimals.
(Please show your work so I know how to do it too! Thanks in advance cuz I am terrible at math...)

Answer 1

Well there are 6 even numbers ( 2,4,6,8,10,12) and 4 odd prime numbers not including “1” (3,5,7,11) so I think the answer you are looking for is 10/12 = .834

Answer 2

$|\Omega|=12\\A=\{2,4,6,8,10,12,3,5,7,11\}\\|A|=10\\\\P(A)=\dfrac{10}{12}=\dfrac{5}{6}\approx0.833$