Question

Suppose that an experiment is repeated four times. A certain event has probability in a single repetition of the experiment.
What is the probability that the event occurs every time in the 4 trials?
What is the probability that it never occurs?
What is the probability that it occurs at least once?
What is the probability that it occurs in the fourth trial only?

Answer 1

1. 4 time p(E) x P(E) x P(E) x P(E)

2. Use complementary events

3. Is the sum of occuring Once, twice, three and 4 times

4. complement x complement x complement x P(E)