Explanation:
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| M' |
|---------------------|
| | |
| | |
| B | MB |
| | |
| | |
|---------------------|
| M |
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Using the diagram, we can find:
M: The number of students who study Maths is 50, so M = 50.
P(M): The probability of selecting a student who studies Maths is P(M) = M / N = 50 / 100 = 0.5.
P(M'): The probability of selecting a student who does not study Maths is P(M') = 1 - P(M) = 1 - 0.5 = 0.5.
P(MNB): The probability of selecting a student who studies both Maths and Biology is P(MNB) = 13 / 100 = 0.13.
P(MUB): The probability of selecting a student who studies either Maths or Biology (or both) is P(MUB) = (M + B - MB) / N = (50 + 29 - 13) / 100 = 0.66.
B: The number of students who study Biology is 29, so B = 29.
P(B): The probability of selecting a student who studies Biology is P(B) = B / N = 29 / 100 = 0.29.
P(MOB): The probability of selecting a student who studies Maths or Biology (but not both) is P(MOB) = (M + B - 2MB) / N = (50 + 29 - 2(13)) / 100 = 0.64.
P(B'): The probability of selecting a student who does not study Biology is P(B') = 1 - P(B) = 1 - 0.29 = 0.71