Question

Maggie’s bank has assigned her a temporary 3-digit PIN to use with her ATM card. Each digit is a number from 1 to 5, inclusive, and no digit can be used more than once in the PIN. Which multiplication problem can be used to determine the probability that the PIN she was assigned was 123?

A 1/5 1/5 1/5
B 1/5 1/4 1/3
C 4/5 3/4 2/3
D 4/5 4/5 4/5

Answer 1

B 1/5 1/4 1/3

Explanation:

The first digit Maggie's bank picked from the 5 digit available, so 1/5.

The second digit will be picked from the 4 remaining digits available, so 1/4.

For the final digit, the bank will have only 3 options to choose from, so 1/3.

So the possibility for the 3-digit assigned PIN to be 123 is

`(1)/(5) * (1)/(4) *(1)/(3) =(1)/(60)`

1/60, so the formula is the one presented in the B option: 1/5 1/4 1/3