Question

The probability that Fiona wakes up before 8am when she does not set her alarm is 2/5 On two consecutive days that Fiona does not set her alarm what is the probability of waking up before 8am for at least one of the days

Answer 1

16/25 = 0.64 = 64%

Explanation:

If we want the probability of Fiona waking up before 8am for at least one of the days, we can calculate the probability of she not waking up 8am in both days, and then we do 1 minus this probability.

The probability of she not waking up 8am in one day is (1 - 2/5) = 3/5

The probability of she not waking up 8am in both days is 3/5 * 3/5 = 9/25

So, the probability of Fiona waking up before 8am for at least one of the days is (1 - 9/25) = 16/25 = 0.64 = 64%