Final answer:
The probability that an employee is not on flex time is 11/30.
Step-by-step explanation:
To find the probability that an employee is not on flex time, we need to calculate the number of employees who are not on flex time and divide it by the total number of employees.
The number of employees not on flex time = Total employees - Employees on flex time. From the information given, there are 100 administrators and 280 staff members on flex time. So, the number of employees not on flex time = (250 + 350) - (100 + 280) = 220.
The probability that an employee is not on flex time = Number of employees not on flex time / Total number of employees = 220 / (250 + 350) = 220 / 600 = 11/30.