Question

A thief steals an ATM card and must randomly guess the correct pin code that consists of 4 digits (0 through 9) that must be entered in the correct order. Repetition of digits is allowed.

What is the probability of a correct guess on the first try?

Answer 1

`(1)/(10000) = 0.0001` probability of a correct guess on the first try.

Explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

Desired outcomes:

Only one correct key, so
`D = 1`

Total outcomes:

4 digits, each with 10 possible outcomes. So

`T = 10^4 = 10000`

What is the probability of a correct guess on the first try?

`p = (D)/(T) = (1)/(10000) = 0.0001`

`(1)/(10000) = 0.0001` probability of a correct guess on the first try.