A repeated digit in the PIN
A 4-digit PIN is chosen with each digit uniform and independent in . What is the probability that at least one digit is repeated (some digit appears more than once)? (to 3 decimals)
Show hints (2)+
- 'At least one repeat' = 1 − P(all four distinct).
- All-distinct count is 10·9·8·7 over 10⁴.
Answer
Reveal answer →Final answer
0.496
Want the full step-by-step worked solution? It's part of Premium - along with a worked solution for every question in the bank.
Asked at: EV & Betting Games, Mixed Quant & Coding