What is probability of language knowledge in company? In a company are 100 workers.


*

*50 of them (100) speak ENG 

*30 of them (100) speak GER 

*15 of them (100) speak ENG and GER


What is the probability of randomly selected worker speaks GER on condition he does NOT speaks ENG?
I have two suggestions:


*

*a) 3/10  

*b) lower than 3/10


As described in the problem, a worker speaking German and a worker speaking English are independent events. As such, the fact that a worker speaks English doesn't actually give you any information as to whether or not a worker speaks German. Thus, the odds that a worker speaks German given that he speaks English is the same as the odds that a worker speaks German: $\frac{3}{10}$ 
