Complete Question:
Frank has a 41% chance of receiving an A grade in statistics, a 36% chance of receiving an A grade in geology, and a 23% chance of receiving A grades in both statistics and geology. Find the probability that he receives an A in statistics or geology (or both) Write your answer as a decimal (not as a percentage).
Answer:
The probability that he receives an A in statistics or geology (or both) is:
0.54
Explanation:
Probability of receiving an A grade in statistics = 41% or 0.41
Probability of receiving an A grade in geology = 36% or 0.36
Probability of receiving A grades in both statistics and geology = 23% or 0.23
Let S = statistics and p(S) = probability of A grade in statistics
Let G = geology and p(G) = probability of A grade in geology
Let p(S and G) = probability of A grades in statistics and geology.
The probability that he receives an A in statistics or geology (or both) is:
= p(S + G) - p(S and G)
= (0.41 + 0.36) - 0.23
= 0.54