Josh has been given two assignments, assignment A and assignment B.He estimates that the chance of getting a passing grade on assignment A is 60% and the chance of getting a passing grade on assignment B is 50%.If Josh gets a passing grade on assignment A, he figures his chances of getting a passing grade on assignment B increase to 70%.How likely is it that Josh gets a passing grade on assignment B but NOT on assignment A?
A).08
B).32
C).20
D).18
E).15

Question

Quizplus · Accepted Answer

.08To find the probability of Josh getting a passing grade on assignment B but not on assignment A, we first need to calculate the probability of him failing assignment A and then getting a passing grade on assignment B. The probability of failing assignment A is 1 - 0.60 = 0.40. Given that he fails assignment A, the probability of passing assignment B remains at 50% (since the 70% chance is conditional upon passing A). Therefore, the probability of this scenario is 0.40 * 0.50 = 0.20. However, this calculation is incorrect based on the initial interpretation. The correct approach should consider the independent probabilities and the conditional probability provided. The correct calculation involves understanding the scenario and the probabilities given, but the initial explanation mistakenly calculated an incorrect scenario. The correct answer is derived from understanding that the probability of B passing without the condition of A passing is independent and initially given as 50%, which needs to be correctly applied within the context of the question.

Josh Has Been Given Two Assignments, Assignment a and Assignment