conway1521 wrote:

Could you clarify how to find Quantity A? It seems to me that the 0.06 you calculate is just the probability of A and B both happening, and doesn't take into account the fact that Quantity A is both OR either. Should quantity A be: P(a)*(1-P(b)) + P(b)*(1-P(a)) + P(a)*P(b) = 0.14+0.18+0.06=0.38 ?

I am quite confused like you.

According to my understanding P(either or both happening) = 1 - P (neither happening)

= 1 - (0.7* 0.8) = 1 -.56 = 0.44

Another way to figure this out is P(A)+ P(B) - P(A*B) = .2+.3-.06 = .44

Maybe I am getting the wording of the question wrong. I don't understand