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Probability
The probability of a certain event is a number expressing the likelihood that a specific event will occur, expressed as the ratio of the number of actual occurrences to the number of possible occurrences. In mathematics, it is a measure of how often an event will happen and is the basis of statistics.
14,643 Questions
What is the probability of rolling a 2 or 5 on a regular number cube?
1/3. The probability of rolling any number is 1/6; if you select two numbers, that's 2/6 of the numbers, or 1/3.
Note: If this question is from work you have been assigned by a teacher or professor, I suggest you do the work yourself instead of trying to find the answers online. This will help you to better understand the material and become more familiar with it. Of course, if this question was not from homework, you can disregard this message.
In case I haven't explained that very well here's an example:
I have a bag containing black and white balls and I think that one quarter of the balls are black. I start drawing balls from the bag (and putting them back afterwards) and I keep drawing out white balls. If I were continue to pick only white balls how many times would this have to happen before I was 90% sure that less than ¼ balls were black?
Thanks
What is the probability of drawing 4 spades from a deck of 52 cards?
The probability of drawing the Four of Spades from a standard deck of 52 cards is 1 in 52, or about 0.01923.
There are 6*14 = 84 possible outcomes.
What is the probability that a coin will land on tails 75 percent of the time if flip four times?
For 4 coin tosses, there are 16 possible outcomes. Tails on 75% of 4 tosses is 3 times tails, and 1 time heads. This occurs in 4 of those 16 possibilities, so the probability is 4/16 = 1/4 (or 25%). But if the question is 'what is the probability that it's tails at least 75% of the time, then you have to add in the 1 where all 4 are tails, then you have 5/16 (or 31.25%).
Suppose the discrete variable X takes the values x where the x belong to some set A. So, for example, if X is the result of a roll of a die then A = {1, 2, 3, 4, 5, 6}.
Then the expected value of X,
E(X) = Sum of [x*Prob(X = x)], where the summation is over all x in A.
In the die example, this would be
1*Prob(X=1) + 2*Prob(X=2) + ... + 6*Prob(X=6)
Let E(X2) = Sum of [x2*Prob(X = x)], where again the summation is over all x in A.
Then Variance(X) = E(X2) - [E(X)]2
and the Standard Deviation = sqrt(Variance).
If X is a continuous variable, then replace Prob(X = x) by the probability density function of X and instead of the summation over A, you will need to integrate with respect to x over the set A.
How long it take to spend a million dollars at 1000 a day?
It would take 1000 days to spend a million dollars at the rate of 1000 dollars per day. (1000 times 1000 is 1000000.) This answer excludes interest accrual, which would make the million dollars last a few days longer.
What is the difference between natural infinite and real infinite set?
A Natural infinite set refers to one whose members can be put into 1-to-1 correspondence with the natural numbers, while a real infinite set is one whose members can be put into 1-to-1 correspondence with the real numbers. Although both sets are infinite, they are not of the same cardinality (size).
The cardinality of the natural infinite set is denoted by À0 or Aleph-null. The cardinality of the real infinite set is 2 to the power À0, which is denoted by C. (Actually Aleph looks like an N with wriggly lines but this browser is incapable of displaying it.)
For more on the cardinality of infinite sets, see the related links. Georg Cantor's diagonal argument is exquisite - simple but immensely powerful. If you want to get a feel for transfinite arithmetic - read about Hilbert's Hotel paradox.
You can't.You don't solve math problems in boxing.You just choose where to punch him.
What is the probability of getting a 5 on a fair number cube and tails on a dime?
1/5 and 1/2.............. 1/10 of getting both in a row
When a fair 6 sided dice is rolled what is the probability of scoring 2?
one in six
same for any number
Which condition is probably most necessary for a monarch to gain power?
That the country remains a monarchy.
Are the values of experimental and theoretical probability same?
Absolutely not. Experimental is practical and theoretically anything is possible.
What are the odds of selecting a four of diamonds out of a deck of fiffty-two card?
The answer depends on the number of draws, whether or not hey are random, whether or not cards are returned to the deck before the next draw.
If only one card that is drawn at random, the probability is 1/52.
How do you predict probability?
"Probability" is not something that occurs in the future. It's the
numerical likelihood of something happening in the future.
You don't predict the probability. You calculate it.
