Question

ILL MEDAL!!!!!!!!!!!!!!!!!!!!!!!!!!!!
A six-sided fair die is rolled 4 times in a row. The probability of getting a 4 only on the last trial is __________

Answer 1

well, what is the probability of not rolling a 4 on the first trial? second trial? third trial? all of those probabilities of independent events must be combined with the probability of then rolling a 4 on the final trial.

Answer 2

another way to approach this is to consider how many possible sequences of 4 rolls there are, and how many of those satisfy the condition of no 4 on the first three rolls, and 1 4 on the last. the number of ways you can roll that divided by the total number of possible rolls is also the probability.