Question

Professor Moore forgets to set his alarm with a probability of 0.10. If he sets the alarm, it will wake him on time to make his first class with a probability of 0.95. If he forgets to set the alarm, he wakes up in time for his first class with a probability of 0.25. what is the probability that professor Moore wakes up in time to make his first class tomorrow?

A) 0.250
B) 0.855
C) 0.880
D) 0.950

Answer 1

C) 0.880

Explanation:

-The probability of setting his alarm is 1-0.1=0.9

-The probability of being in time is therefore calculated as:

`P=P(set\ alarm)P(In \ time)+P(Not \ set \ alarm)P(in \ time)\\\\=0.9* 0.95+0.1* 0.25\\\\=0.88`

Hence, the probability that the professor shows up in time is 0.88