Answer
$P(three~of~a~kind)=\frac{54,912}{2,598,960}=0.02113$
Work Step by Step
From (a): $N(S)=2,598,960$
From (b): $N(3~of~the~same)=52$
From (c): $N(2~different~cards)=1056$
Using the Multiplication Rule of Counting (see page 298):
$N(three~of~a~kind)=N(3~of~the~same)\times N(2~different~cards)=52\times1056=54,912$
Using the Classical Method (page 259):
$P(three~of~a~kind)=\frac{N(three~of~a~kind)}{N(S)}=\frac{54,912}{2,598,960}=0.02113$
