John is taking Statistics and Biology this semester. The probability John will get an A in Statistics is 0.4. The probability John will get an A in Biology is 0.3. The probability John will get an A in both Statistics and Biology is 0.15. What is the probability that John will get at least one A between his Statistics and Biology courses?
A) 0.12
B) 0.15
C) 0.55
D) 0.7

Question

Quizplus · Accepted Answer

The probability of getting at least one A is the sum of the probabilities of getting an A in Statistics and the probability of getting an A in Biology minus the probability of getting an A in both Statistics and Biology. So, the probability of getting at least one A is 0.4 + 0.3 - 0.15 = 0.55.

John Is Taking Statistics and Biology This Semester