SOLUTION: Among 30 secretaries of several faculties in a university each of them speaks at least one foreign language English,french or russian. There are 11 secretaries speaking english, 6

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Question 834462: Among 30 secretaries of several faculties in a university each of them speaks at least one foreign language English,french or russian. There are 11 secretaries speaking english, 6 speaking french and 2 speaking russian. Moreover, it is known that 7 of these secretaries speak exactly 2 of the 3 languages and 21 speak English. Denote by E the set of secretaries speaking english by F for french and R for russian. Find
a) the number speaking all 3
b) the number speaking both french and russian but bot english.
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
You state first that 11 speak English and later that 21 speak English