In a certain office, 50 percent of the employees are college graduates and 60 percent of the employees are over 40 years old. If 30 percent of those over 40 have master's degrees, how many of the employees over forty have master's degrees?

1- Exactly 100 of the employees are college graduates

2- Of the employees forty years old or less, 25 percent have master's degrees

Statement 1 is sufficient.

My answer assumes that all employees with a masters degree are also college graduates. Using a grid to analyze this problem is helpful. Please see the attached spreadsheet.