What is the probability of rolling a number greater than or equal to 5 on a six-sided die?

To determine the probability of the complement of rolling a number less than 5 on a six-sided die, we first need to understand what this means.

A standard six-sided die has the following possible outcomes: 1, 2, 3, 4, 5, and 6. The numbers less than 5 are 1, 2, 3, and 4. Therefore, when we talk about rolling a number less than 5, we are referring to these four outcomes.

The probability of rolling a number less than 5 can be calculated as follows:

• Number of favorable outcomes (rolling less than 5): 4 (the numbers are 1, 2, 3, 4)
• Total number of possible outcomes when rolling a die: 6

So, the probability of rolling a number less than 5 is:

P(less than 5) = Number of favorable outcomes / Total outcomes = 4 / 6 = 2 / 3

Now, the complement of this event is rolling a number that is greater than or equal to 5, which includes the outcomes 5 and 6.

The probability of the complement (rolling a number greater than or equal to 5) is therefore:

• Number of favorable outcomes (rolling 5 or 6): 2

P(greater than or equal to 5) = Number of favorable outcomes / Total outcomes = 2 / 6 = 1 / 3

In conclusion, the probability of rolling a number greater than or equal to 5 on a six-sided die is 1/3.