probability question

Question

A red die is tossed and then a green die is tossed. What is the probability that the red die shows an even number or the green die shows an even number? 

Answer 1

Hi Emely, there are three even numbers on a die.

 

The probability of rolling an even number on the red die is: p(red with even) = 3 / 6, or 1 / 2, since there are six numbers on a die.

 

The probability of rolling an even number on the green die is the same as the probability of rolling an even number on the red die, or 3 / 6, or 1 / 2.

 

Since rolling the red die and rolling the green die are independent events, to find the probability of both occurring, you need to multiply the individual probabilities.

 

P(of both red and green even) = 1/2 * 1/2, or 1/4.

 

Questions?

Answer 2

The only way that this event (one or both even) does not occur is when both red & green are ODD...that will happen just ¼ of the time, so P(red even or green even) must be ¾.