A Standard Admissions Test Was Given at Three Locations

Short Answer

A standard admissions test was given at three locations. One thousand students took the test at location A, 600 students at location B, and 400 students at location C.The percentages of students from locations A, B and C who passed the test were 70%, 68% and 77%, respectively.One student is selected at random from among those who took the test.
a.What is the probability that the selected student passed the test?
b.If the selected student passed the test, what is the probability that the student took the test at location B?
c.What is the probability that the selected student took the test at location C and failed?