Question

Every Monday, James has a math class and a biology class. The probability that he will have his math homework done is 0.48 and the probability he will have his biology homework done is 0.57. If the probability he will have his biology homework done but not his math homework is 0.27, what is the probability he will have his math homework done but not his biology?

Answer 1

M=	maths
B=	biology
so we have
P(M) = P(M∩B) + P(M∩B') = 0.48
P(B) = P(B∩M) + P(B∩M') = 0.57
The probability he will have his biology homework
done but not his math homework is 0.27
so     P(B∩M') = 0.27
P(B∩M) + P(B∩M') = 0.57
P(B∩M) + 0.27= 0.57
P(B∩M) = 0.30
P(M∩B) = P(B∩M) = 0.30
P(M∩B) + P(M∩B') = 0.48
0.30 + P(M∩B') = 0.48
P(M∩B') = 0.18 Answer