Question

Plzzzzzzzzzzzzzz! A personal identification number (PIN) is a 4 digit code. A local bank only allows the numbers 1, 2, 3, 4, 5, 6, 7, 8, and 9 to be used. What is the probability that a randomly chosen PIN starts with 7 followed by 2 and doesn't contain the same number twice? Enter your answer as a fraction in simplest form.

Answer 1

14/2187

Explanation:

Let us first see how many possible outcomes there are. We can to that by multiplying 9^4. This gives us 6561.

Now, we can see what are the possible outcomes that meet the requirements. We can get this by multiplying 1 • 1 • 7 • 6, which is 42.

Our fraction is 42/6561, which is 14/2187.

Hope this helped!