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

Answer 1

First digit fixed (3) → 1 choice. Second digit 2 choices (4 or 7). Third and fourth each 10 choices (0–9). Total = 1 × 2 × 10 × 10 = 200. Answer: d.