A box contains one yellow, two red, and three green balls. Two balls are randomly chosen without replacement. Define the following events:

$A: \lbrace$ One of the balls is yellow $\rbrace$
$B: \lbrace$ At least one ball is red $\rbrace$
$C: \lbrace$ Both balls are green $\rbrace$
$D: \lbrace$ Both balls are of the same color $\rbrace$

Find the following conditional probabilities:

(a) $P(B|A)$ $=$
(b) $P(D|\overline{B})$ $=$
(c) $P(C|D)$ $=$