I worked this simple problem and am not sure if it is correct and I have another 19 questions similar to this therefore I need to be sure of what I am doing.

The problem broken in simple terms..

company paced order for 2 products

event E => 1st product out of stock Pr(E)=0.3

event F => 2nd product out of stock Pr(F)=0.2

P(E or F) = 0.2

a) Pr( both out of stock) => (Pr(E)*(Pr(F)) = (0.3*0.2)= 0.6

b) are e and f independent => I think they are independent since e has nothing to do with f. (I am not sure if this is the correct reason). But if they were independent why should they have an intersection. Pr(EandF)

c) p(F given E) => P(F|E) = P(F and E) / P(E) = 0.6/0.3 and here I noticed I have worked wrong since Pr can never be greater than 1

well , should I reduce p(e or f)=0.4 thus

ans a ) 0.3*0.2-0.4 ??

Thanks in advance