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.
It is 0.5
It is 0.5
The probability when you roll two dice that you roll an odd number on the first die and a 1 on the second die is 1 in 12. The two die are sequentially unrelated, so you can consider them separately. The probability of rolling an odd number is 3 in 6, or 1 in 2. The probability of rolling a 1 is 1 in 6. Multiply the two probabilities together and you get 3 in 36, or 1 in 12.
Assuming you are talking about fair, six-sided dice, then the probability of rolling a 1 on the first roll in 1/6, and the probability of rolling a 2 on the second roll is 1/6. Putting these together, the probability of rolling 1 on the first die and 2 on the second die is 1/36. If you do not care about the order, then you could roll 1,2 or 2,1; in this case the probability would be 2/36, or 1/18.
If the die is fair then for a single roll, the probability is 1/2.
It is 1 (a certainty) if you roll it often enough. For a single roll of a fair die, the probability is 1/6.
3/6
It is 0.5
0.25 ( P = 0.5 each time)
5 out of 12
It is 0.5
One out of two
1 out of 2 if the die is six-sided.
1 out of 2
Since there is only one even prime, 2, the probability of rolling a 2 with one die is 1 in 6.
With a fair die it is 5/6.
The probability of rolling a number on a die is 1 out of the number of sides on the die. So, for a six sided die, the probability of rolling a 4 is 1/6. The probability of rolling a 4 or a 5 becomes 2/6 or 1/3. This is because there are two acceptable outcomes out of six. So when finding the probability of rolling a number less than x on a y sided die, it becomes x-1 / y. It is x-1 because the outcome is to roll less than the number, not less than or equal.