Question

5. John and Mary are taking a math course. The course has only 3 grades: A, B, and C. The probability that John gets a B is 0.3 .The probability that Mary gets a B is 0.4 . The probability that neither gets an A but at least one gets a B is 0.1 .What is the probability that at least one gets a B but neither gets a C

Answer 1

0.6

Explanation:

In the question, we are told that:

The probability that John gets a B is 0.3 .

The probability that Mary gets a B is 0.4 .

The probability that neither gets an A but at least one gets a B is 0.1

The probability that at least one gets a B but neither gets a C

=( The probability that John gets a B ) +( The probability that Mary gets a B )- (The probability that neither gets an A but at least one gets a B is 0.1

= 0.3 + 0.4 - 0.1

= 0.7 - 0.1

= 0.6

Therefore, the probability that at least one gets a B but neither gets a C is 0.6