Records of a Company Show That 15% of the Employees

Short Answer

Records of a company show that 15% of the employees have only a high school diploma (H), 75% have bachelor degrees (B), and 10% have graduate degrees (G). Of those with only a high school diploma, 12% hold management positions; whereas, of those having bachelor degrees, 58% hold management positions. Finally, 82% of the employees who have graduate degrees hold management positions.
a.What percentage of employees holds management positions?
b.Given that a person holds a management position, what is the probability that she/he has a graduate degree?