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 3 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

Rationale: 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 = 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 = 39 . answer : a
Answer: A