Question

A bag has one white, two black, three red and four green marbles. If a single marble is randomly drawn from this bag, what is the probability it is black or white? Express your answer as a common fraction.

Answer 1

3/10

Explanation:

This is mutually exclusive, meaning they cannot happen at the same time, you cannot pickup a marble and it cant be both black and white. So all we do now is just add the probabilities of getting a black marble and white marble

P(picking a black marble) = 2/10

P(picking a white marble) = 1/10

Add them

2/10 + 1/10 = 3/10