What are the odds and probability of rolling 5 dice, and all 5 dice are the same number?

2 Answers

1/6^4=1/1296

Explanation:

There are six faxes with six distinct numbers. For each dice, the
probability is (number of favorable cases)/(the total number of all possible cases).
Because any first roll is favorable, this probability can be modeled by:
=6*1/(6^(n) or 1/(6^(n-1))

For all showing the same number, it is the compound probability
= product of the separate probabilities.
=1/(6^(5-1))
=1/6^4

May 7, 2018

P("all 5 dice show the same number") = 1/1296

Odds are 1:625

Explanation:

Let's look at the probability first.

P(5 " dice give the same number")

They must be all 1s or all 2s or all 3s ... and so on

=P(1,1,1,1,1) +P(2,2,2,2,2)+......... + P(6,6,6,6,6)

(1/6xx1/6xx1/6xx1/6xx1/6) + ....+(1/6xx1/6xx1/6xx1/6xx1/6)

= 1/6^5 + 1/6^5 + .......... +1/6^5

= 6 xx 1/6^5

=1/6^4 = 1/1296

The odds are given as a ratio of the number of ways this will happen compared to the number of ways it doesn't.

So if the first die is 1, the other four will not be,

6 xx (1/6 xx5/6xx5/6xx5/6xx5/6) = 625/1296

The odds for this happening are 1 : 625