Skip to main content
OlympiadHQ

Browse · harp

Print

jmc

counting and probability junior

Problem

An ATM password at Fred's Bank is composed of four digits from to , with repeated digits allowable. If no password may begin with the sequence then how many passwords are possible?
(A)
(B)
(C)
(D)
Solution
For the first three digits, there are combinations since is not allowed. For the final digit, any of the numbers are allowed. .
Final answer
D