Question

A new secretary has been given n computer passwords, only one of which will permit access to a computer file. Because the secretary has no idea which password is correct, he chooses one of the passwords at random and tries it. If the password is incorrect, he discards it and randomly selects another password from among those remaining, proceeding in this manner until he finds the correct password. (a) What is the probability that he obtains the correct password on the first try?

Answer 1

P=1/N

Explanation:

Probabilities can be numerically described by the number of desired outcomes divided by the total number of all outcomes:

Only one is correct and there are N possible choices.

So the answer is: 1/N