Question

A thief steals an ATM card and must randomly guess the correct five-digit pin code from a 7-key keypad. Repetition of digits is allowed. What is the probability of a correct guess on the first try?

Answer 1

1/(7^5)=1/16807

Explanation:

Assuming 7-key mean zero up to 7,

# of possible codes = 17^5 = 16807

=====

Probability of first try correct = 1/7^5