Records of a Company Show That 20% of the Employees

Short Answer

Records of a company show that 20% of the employees have only a high school diploma; 70% have bachelor degrees; and 10% have graduate degrees. Of those with only a high school diploma, 10% hold management positions; whereas, of those having bachelor degrees, 40% hold management positions. Finally, 80% 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?