2 A friend tells you that his email password consists of two

2. A friend tells you that his email password consists of two capital letters, followed by two digits, then ending with a lower-case letter. What is the probability that you guess the password correctly on the first try?

Solution

There are 26^2 ways to choose the first two letters, and 10^2 ways to choose the next two digits, and 26 ways to choose the last letter.

Thus, there are (26^2)*(10^2)*26 = 1757600 ways to guess.

Thus, the probability is

P = 1/1757600 or 0.000000568958 [ANSWER]