Don't understand this conditional probabillity example

[thisischris]

At the bottom of the page (example 2) for question c) P(B|A').

They say P(B n A') = 0.2. But surely it is (B while not A) which in my mind should be 0.15.

Can somebody tell why it is 0.2?

 

[Ray Vickson]

At the bottom of the page (example 2) for question c) P(B|A').

They say P(B n A') = 0.2. But surely it is (B while not A) which in my mind should be 0.15.

Can somebody tell why it is 0.2?

If the diagram is correct, and if my interpretation of the various numbers there is correct, it should be 0.15, as you want.

RGV

 

[thisischris]

Thank you!