Question

An identity thief watches someone enter a four-digit PIN and manages to see that the first digit is 3. They also know that the second digit is either 4 or 7. If the thief tries guessing the PIN, how many possiblities would there be? a. 100 b. 162 c. 180 d. 200 Please select the best answer from the choices provided. A B C D.

Answer 1

Answer:

B

Step-by-step explanation:

First, we know that there's exactly one choice for the first digit.

Then, we'll look at the second digit. There are two choices for this.

Next, we'll look at the third and fourth digits. From 1 through 9, there are 9 numbers, and hence nine choices for each digit.

We'll work out the number of possibilities by taking the product of the individual possibilities:

$1*2*9*9=162$

So the answer is B.