1.) A metropolitan school system consists of two districts- north and south. the north district contains 60% of all students, and the south district contains 40% of all students. a minimum competency test was given to all students. 10% of the north district students failed, and 15% of the south district students failed.

What is the probability that a student who has failed the test came from the south district?

a.) 0.15
b.) 0.40
c.) 0.50
d.) 0.75