# Does order matter in n choose k

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## Does order matter in combinations?

If the order doesn’t matter then we have a combination, if the order do matter then

**we have a permutation**. One could say that a permutation is an ordered combination. The number of permutations of n objects taken r at a time is determined by the following formula: P(n,r)=n!## Does order matter in selection?

They cannot be made from the same group (contrary to the first question). It

**doesn’t matter whether you**catch hold of the man first or the woman first. In the first question, the probability of picking the correct second number depends on what you picked in the first selection. Hence we consider the order.## Does order matter why or why not?

**Yes**, order matters in a permutation. Order is what distinguishes one permutation from another.

## How do you know if order matters in permutations?

Permutations are for lists (order matters) and combinations are for groups (order doesn’t matter). You know, a “combination lock” should really be called a “

**permutation lock**“. The order you put the numbers in matters. A true “combination lock” would accept both 10-17-23 and 23-17-10 as correct.## Does order matter in list?

In short,

**yes, the order is preserved**. In long: In general the following definitions will always apply to objects like lists: A list is a collection of elements that can contain duplicate elements and has a defined order that generally does not change unless explicitly made to do so.## Does the order matter?

In math,

**order always matters unless it is specified otherwise**. As an example: the order of operations always matters unless we know that specific operators are commutative. For example, is the same as , because addition of integers is commutative.## Does order matter in sample space?

Well, it could be the first coin landed on heads and the second tails (HT) or the other way around (TH). Notice that when we deal with sample spaces,

**the order is important**!## Does order matter without replacement?

r! We divide by r! to reduce the number of combinations repeated since order is not important. … Since order does not matter and there is no replacement,

**we use combinations**.## Why does the order of addition not matter?

Addition has several important properties. It is

**commutative**, meaning that order does not matter, and it is associative, meaning that when one adds more than two numbers, the order in which addition is performed does not matter (see Summation).## Does order matter for probability?

The

**order does not matter when the variables**are independent random variables, i.e., when the probability of one variable does not depend on the outcome of the previous. The order when a previous even influences the current one.## How do I choose without replacing?

**Sampling**without Replacement is a way to figure out probability without replacement. In other words, you don’t replace the first item you choose before you choose a second. This dramatically changes the odds of choosing sample items.

## Do permutations allow repetition?

Permutations: order matters,

**repetitions are not allowed**.## What is sampling with and without replacement?

For example, if

**one draws a simple random sample such that no unit occurs more than one time in the sample**, the sample is drawn without replacement. If a unit can occur one or more times in the sample, then the sample is drawn with replacement.## Should sampling be with replacement?

When we sample with replacement,

**the two sample values are independent**. Practically, this means that what we get on the first one doesn’t affect what we get on the second. Mathematically, this means that the covariance between the two is zero. In sampling without replacement, the two sample values aren’t independent.## What is the probability with replacement?

Probability with Replacement is

**used for questions where the outcomes are returned back to the sample space again**. Which means that once the item is selected, then it is replaced back to the sample space, so the number of elements of the sample space remains unchanged.## Why are the with replacement and without replacement probability different?

The difference between drawing with replacement and without replacement is

**the sample space and the probabilities you get out of the space**. If you are drawing from a set of objects X with replacement n times, then the sample space is the cartesian product Xn.## When sampling without replacement if the sample size is less than?

sampling without replacement. When sampling without replacement, if the sample size is less

**than 5% of the population**, the sampled items may be treated as independent. Two events are mutually exclusive if they cannot occur at the same time.## Why is bootstrapping done with replacement?

The bootstrap method is a resampling technique

**used to estimate statistics on a population by sampling a dataset with replacement**. It can be used to estimate summary statistics such as the mean or standard deviation. … That when using the bootstrap you must choose the size of the sample and the number of repeats.Ads by Google