Year 12s: what will be the first way you research your future options? >>

Not sure of the answer (Venn Diagrams).

Howdy

. I have attached the question and answers I am working on.

I don't understand part b(ii). I get that P(B U T) is 10 + 8 + 4 + 6 + 11 + 3 = 42 which is the bottom part of the fraction as of the 'given by |' part.

I just don't get why we only use 15 for P(Z)

Wouldn't we take all the Z values for P(Z). 15 + 3 + 4 + 8.

I just don't get how we take 15 for the numerator. Could some please explain?

Thanks

Reply 1

username1750195

Original post by jojo55

Howdy

You need to use the rule P(A|B) = P(A n B)/P(B)

Identify which bit of the Venn Diagram gives you P(Z n (B u T)), and which bit gives you P(B u T), then divide

Both probabilities will be out of 70, so you can do some cancelling.