Question

you roll a number cube twice. Find P(even, then not 2). Write the probability as a fraction in simplest form.

Answer 1

The most important is to interpret (understand) the question.

You are asked to find the probability that the first roll is an even number and the second roll is not 2.

The joint probability is the product of both probabilities.


1) Probability that the first roll is even:

Three outcomes out of 6 are even: 3/6 = 1/2


2) Probability that the second roll is not 2.
 
Five outcomes out of 6 are no 2: 5/6


3) Joint probability = 1/2 * 5/6 = 5/12


Answer: 5/12