Question

You roll a number cube three consecutive times. What is the probability that you roll an even number the first two times and a 3 the last time?

Answer 1

1/24

Explanation:

A die has 6 faces with numbers 1 through 6. Three faces have even numbers, and 3 faces have odd numbers.

Each roll of the die can result in 6 different outcomes.

The total number different outcomes of rolling a die 3 times is 6 * 6 * 6 = 216.

There are 3 possible even number outcomes on the first roll, and another 3 possible even number outcomes on the second roll. The third roll needs to be a 3, so there is one single desired outcome of the third roll.

Total number of desired outcomes: 3 * 3 * 1 = 9

probability(even, even, 3) = 9/216 = 1/24

Answer 2

1/24.

Explanation:

Probability(Rolling an even number)

= 3/6 = 1/2.

Probability(Rolling a 3) = 1/6.

Required Probability = 1/2 * 1/2 * 1/6

= 1/24.

The probabilities are multiplied because the 3 events are independent.