Question

PLZ HELP IM 2 WEEKS BEHIND. MY SCHOOL CALLED MY MOM

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?

I dont want to know the probability i just want to know how to get it. here the options


(1/5) (1/5) (1/5)

(1/5) (1/4) (1/3)

(4/5) (3/4) (2/3)

(4/5) (4/5) (4/5)

Answer 1

Answer: You multiply the probability of each "event" -- the selection of the desired number, by the probabilities of the other events.

Explanation:

The probability of getting 1 as the first number is 1/5 (possibilities are 1,2,3,4,5)

The probability of getting 2 as the second number is 1/4 (possibilities are 2,3,4,5. 1 is gone)

The probability of getting 3 as the third number is 1/3 (possibilities are 3,4,5. 1 and 2 are gone)

So you multiply 1/5 × 1/4 × 1/3