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The answer depends upon what you are rolling.
The probability is calculated as:
number_of_ways_of_success ÷ total_number_of_outcomes
There can be shortcuts to finding the number of ways of a successful outcome (for this problem it is a roll of less than 10), but it may end up at having to list out all the possible outcomes and counting the ones which are a success; in this case it may be less to find if the number of failures is instead calculated and the probability of a failure subtracted from 1 since probability_of_success + probability_of_failure = 1
If you are rolling 2 standard dice, there are 36 possible outcomes. A success is if the sum is less than 10, so a failure is if the sum is 10 or more:
12 - can be made only 1 way: (6, 6)
11 - can be made 2 ways: (5, 6), (6, 5)
10 can be made 3 ways: (4, 6), (5, 5), (6, 4)
→ there are 1+2+3 = 6 ways of failure
→ probability(failure) = pr(roll ≥ 10) = 6/36 = 1/6
→ probability(success) = pr(roll < 10) = 1 - pr(failure) = 1 - pr(roll ≥ 10) = 1 - 1/6 = 5/6.
With an icosahedral die (as used by D&D players) with the numbers 1-20 on it, the probability of rolling less than 10 would be 9/20 as there are 9 numbers (1-9) less than 10 and there are 20 possible outcomes.
If this is with two standard 6 sided dice, then you have 36 outcomes: from 1+1 = 2, up to 6+6=12.
Let's look at the ones which are 10 or greater: 12 (only 1), 11 (there are 2, 5+6 and 6+5), 10 (there are 3: 5+5, 6+4, 4+6), all other rolls will be less than 10.
So we have 6 outcomes which are 10 and up, therefore you have 30 outcomes which are less than 10, so the probability is 30/36 which is 5/6, or about 83%.
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What is the probability of rolling a number less than 4 on a 6-sided number cube labeled 1-6?
3 out of 6, or 50%
A die is tossed. Find the odds against rolling a number greater than 1.?
The probability of rolling a number greater than 1 is 5/6.
What is the experimental probability of rolling an even number?
The experimental probability of anything cannot be answered without doing it, because that is what experimental probability is - the probability that results from conducting an experiment, a posteri. This is different than theoretical probability, which can be computed a priori. For instance, the theoretical probability of rolling an even number is 3 in 6, or 1 in 2, or 0.5, but the experimental probability changes every time you run the experiment.
The probability of rolling a number greater than 5 on one roll of a die?
Only 6 is greater than 5 on a standard cubic die. The chance of rolling a 6 is one in six.
A pair of dice is rolled find the probability One die shows a 6 and the other is a number less than 5?
There are 62 or 36 outcomes for rolling 2 dice. The outcomes that meet the criteria specified are: 1,6 2,6 3,6 4,6 6,4 6,3 6,2 6,1. So the probability of one die shows a 6 and the other is a number less than 5 is 8/36 or 2/9.
What is the probability of rolling a number less than 1?
The probability of rolling a number less than 1 on a standard 6-sided die is zero. It will not happen.
What is the probability of rolling a number less than five on a standard number cube?
There is a 4 in 6 (or 2 in 3) probability of rolling a number less than a five on a standard number cube.
When rolling a number cube what is the probability of rolling a number less than 3?
It is: 1 in 3
What is the question of the problem if rolling a number cube labeled from 1 to 6 and the probability is one half?
There could be many questions: What is the probability of rolling an even number. What is the probability of rolling an odd number. What is the probability of rolling a number less than 4. What is the probability of rolling a number more than 3. What is the probability of rolling 1,4, or 6. Basically it could be any question about the probability of rolling half of the faces.
What is the probability that the number rolled will be less than 6?
The probability of rolling a number less than 6 on a die would be 5/6.
What is the probability of rolling a number less than or equal to 12 when rolling two number cubes?
It is 1.
When rolling three number cubes what is the probability of rolling a 5a number less than 3and an even number?
The probability is 57/216 = 19/108
What is the probability of rolling a number less than 3 and greater than 4 with one roll of a number cube?
The probability is zero. No number can be less than 3 and greater than 4.
How do you find the probability of rolling a number less than a certain number on one roll of a die?
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.
What is the probability of rolling a number less than 8 on a fair six sided dice?
The probability is 1.
What is probability of rolling a number less than or equal to 2 on then number cube?
It is 1/3
What is the probability of rolling a number less than 4 on a fair number cube?
3 out of 6
