Question

A deck of twelve cards contains the numbers 1 through 12. Find the theoretical probability with replacement. Express your answer as a simplified fraction.

P(9, 12) = __

Answer 1

Answer: 1/144

Step-by-step explanation

There's only one card labeled "9" out of the 12 cards total.

1/12 = theoretical probability of getting a "9"

1/12 is also the theoretical probability of getting a "12" for very similar reasoning.

When the cards are put back, aka replacement, we multiply those fractions.

(1/12)*(1/12) = (1/12)^2 = 1/144 is the theoretical probability of getting "9" then getting "12", when replacement is done.

Extra info: 1/144 = 0.0069444 = 0.69444% approximately, where the '4's go on forever.