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

Answer:

$\frac{1}{10000} = 0.0001$ probability of a correct guess on the first try.

Step-by-step 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?

$p = \frac{D}{T} = \frac{1}{10000} = 0.0001$

$\frac{1}{10000} = 0.0001$ probability of a correct guess on the first try.