There are 50 employees in the office of ABC Company. Of these, 22 have taken an accounting course, 14 have taken a course in finance and 15 have taken a marketing course. 10 of the employees have taken exactly two of the courses and 1 employee has taken all three of the courses. How many of the 50 employees have taken none of the courses?	Choices:
A) 11 B) 5 C) 9 D) 8 E) 10
50 Employees. Counting every different attendand to the courses we have:   Accounting: 22   Finance: 14   Marketing: 15   Which would add up to 51 different attendands, which is not possible.   Now 10 have taken exactly 2 courses, which means that there are 10 less different attendands. Say that 10 of the Finance attentands also attended Accounting.   51-10= 
<gadget id="calculator">51-10</gadget>
<output>41</output>
41   1 Person has taken all three courses. As above, we subtract him from the number of different attendands. Since this time the person took all three courses, we have to substract him two times.   41-2= 
<gadget id="calculator">41-2</gadget>
<output>39</output>
39.   11nswer : 11
<result>A</result>
There are 50 employees in the office of ABC Company. Of these, 22 have taken an accounting course, 14 have taken a course in finance and 15 have taken a marketing course. 10 of the employees have taken exactly two of the courses and 1 employee has taken all three of the courses. How many of the 50 employees have taken none of the courses?