What the probability that some body rolled a 3 both times on a number cube?

1 Answer
May 30, 2018

#=>1/36#

Explanation:

A cube has six faces. Assuming all faces are unique (as on a traditional number cube), the number #3# appears only once. That means there is a #1/6# probability of rolling a #3# once.

Since consecutive rolls of the cube are independent events (no event affects a future event), compound probability is computed as a product of the individual probabilities of all events.

So for roll 1, probability of #3# is #1/6#.

For roll 2, probability of #3# is also #1/6#.

Total probability of getting #3# on both roll 1 and roll 2 is:

#=1/6 xx 1/6 = 1/36#