Question

If you roll a standard number cube, determine the probability that you roll an even number or a 5.

A. 1/6
B. 1/2
C. 1/12
D. 2/3

Answer 1

To find the probability of rolling an even number or a 5 on a standard number cube, we first identify the possible outcomes.

A standard number cube has six faces numbered from 1 to 6. The even numbers on the cube are 2, 4, and 6.

The outcomes are:
- Even numbers: 2, 4, 6 (3 outcomes)
- Number 5: (1 outcome)

Next, we find the total outcomes in the event of rolling an even number or a 5. The outcomes we have are:
- 2
- 4
- 6
- 5

These outcomes are distinct. Thus, the total number of favorable outcomes is 4 (2, 4, 5, and 6).

The total number of possible outcomes when rolling a standard number cube is 6 (since the cube has six sides).

We calculate the probability as follows:

\[
P(\text{even number or 5}) = \frac{\text{Number of favorable outcomes}}{\text{Total number of possible outcomes}} = \frac{4}{6} = \frac{2}{3}
\]

Thus, the probability that you roll an even number or a 5 is \(\frac{2}{3}\).

The answer is D. \(\frac{2}{3}\).