Find probability of event Task is: Find probability of 4 aces laying in row in a deck of 36 cards.
All possible shufflings of 36 deck is $36!$ I can place 4 cards in a row with $33$ different ways. And each way can be $4!$ altered because, we don't care in what order 4 aces are. 
So probability is: $$\frac{33\cdot4!}{36!}$$
Answer does not match with answer in a book. Where am I wrong? Thank you!
[EDIT]
Book's answer is $\frac{1}{1785}$
[/EDIT]

Placing $36$ cards in a row can be done on $36!$ ways. If we add the condition that the first $4$ cards are aces then it can be done on $4!32!$ ways. If we add the weaker condition that the aces must be adjacent then it can be done on $33.4!32!$ ways. So there is a probability of: $$\frac{33.4!32!}{36!}=\frac1{1785}$$ that it happens.
