What is the probability of rolling an odd number on 1 roll of die?

Answer 1

With a single die:

There are 6 sides on a dice.

There are 3 sides that are odd (1, 3, 5)

3/6 = 1/2 = 50%

Therefore, a single die has a 50% chance of landing on an odd number.

If you have two dice:

I'll explain this the longer way, however there are short (and simpler explanations) that basically use the fact that a single die is 50%, therefore two independent dice will also be 50%.

Number of dice = 2Sides of a dice = 6

Odd sides: 1, 3, 5, so Number of odd sides on a dice = 3

Even sides: 2, 4, 6, so Number of even sides = 3

Total combinations with two 6 sided dice = (sides on dice x sides on dice) = 6 x 6 = 36

We need to take the fact that:

An odd number + an odd number = even
An even number + an even number = even

An odd number + an even number = odd <--- we want this case

Odd combinations on a dice:

First dice is even, second dice is odd (even sides x odd sides):

(3) x (3) = 9

First dice is odd, second dice is even (odd sides x even sides):

(3) x (3) = 9

Total odd combinations:

9 + 9 = 18

Divide odd combinations by total combinations to get the probability:

18 / 36 = 1/2

You have a 50% chance to roll an odd number on a single roll of two six sided dice.