tree diagram , any one great with these?

please standby while I attach the problem

Question

tree diagram , any one great with these? 

please standby while I attach the problem

anonymous · Answer

attachment

unklerhaukus · Answer

$$P(A|D)=x× r$$

anonymous · Answer

it didn't work :(

unklerhaukus · Answer

oh, i was reading the notation incorrectly,

P(A|D)   means the probability that A occurs , given that D occurs

anonymous · Answer

how do I do that do I have to multiply by 100??

unklerhaukus · Answer

there are two cases that D occurs       y-B-t-D

                                                   and x-A-r-D


we know D has occurred,     
the only thing we aren't sure about is as it through    x or y?

unklerhaukus · Answer

to get A it must have been through the x branch,   what is the probability of this ?

unklerhaukus · Answer

i think it's just   $x$