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

Each year, on Groundhog's Day, February 2nd, everyone awaits the appearance of the groundhog. As the story has it, if he emerges from his hole and if it is sunny, he will be startled by his own shadow and quickly retreat back into his hole. This signals six more weeks of winter. However, if it is a cloudy day and he sees no shadow, spring-like weather will come early.

There is a 25% chance that the groundhog will see his shadow on February 2. The probability of spring coming early if the groundhog sees his shadow is 20%; the probability of spring coming early if the groundhog does not see his shadow is 60%. Suppose that spring comes early this year. What is the probability that the groundhog saw his shadow on February 2?

a. 50%

b. 12%

c. 10%

d. 5%

e. 2%