posted by Sharon on .
At a certain college, 15% of the students receieved an A in their required math cousre, 10% receieved an A in their required chemistry course, and 5% receieved an A in both. A student is selected at random.
a.) What is the probability that he received an A in either chemistry or math?
b.) What is the probabilty that he receieved an A in chemistry, if he ahd an A in math?
c.) what is the probaility that he receieved an A in math, if he had an A in chemistry?
d.) Are th events " A in math" and "A in chemistry" independent?
Draw a venn diagram.
a) P(C or M) = P(C)+P(M)-P(C and M) = .10 + .15 - .05 = 20%
b) 15% got an A in Math, 5% both, or 33.33% of those that got an A in Chem.
c) repeat logic in b)
d) if they were independent, the prob of getting A's in both would be P(C)*P(M)
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