Probability Question

Question

If Lilly has a probability of a each day of having a surprise quiz, then in terms of a, what is the probability that Lilly has at least one quiz in a three day school week?

Answer 1

Probability of not having a quiz in a day is 1-a

probability of no quizzes in a 3 day week is (1-a)³

probability of at least one quiz in a 3 day week is 1 - (1-a)³