Answer
See below.
Work Step by Step
a) In this case the events are independent: $\frac{13}{52}\frac{13}{52}\frac{13}{52}=\frac{1}{64}$
b) In this case the events are not independent: the first one has probability $\frac{13}{52}$; the second one has probability $\frac{13}{51}$; and the third one has probability $\frac{12}{50}$. Thus the probability is: $\frac{13}{52}\frac{13}{51}\frac{12}{50}=\frac{13}{850}$
