Having typed the first letter of Hamlet, the probability of the next letter being correct is 1/61 if our monkey has a normal keyboard with 61 keys, and he is equally able to hit any of them. It is always the same 1/61 chance that the next character will be right.

Let’s guess that there are 6000 words in Hamlet, of average length 5 characters. That means 30,000 characters. Make it 33000 to provide for spaces and punctuation.

The probability that our monkey will proceed to type this version of Hamlet is 1/61 to the power of 32000

Wolfram Alpha gives the answer as 1.304501... × 10^-58916

So don’t hold your breath.