A combination is a way of selecting several things out of a larger group, where order doesn't matter.
The key thing to remember with combinations is that order DOESN'T matter.
The combination general formula is the number of distinct combinations of "r" items selected (without replacement) from a pool of "n" items, denoted by nCr
The n and r in the formula stand for the total number of objects to choose from and the number of objects in the arrangement.
A combination of items occurs when:
* the items are selected from the same group
*No item is used more than once
*The order of items makes no difference
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Combination problems involve situations in which the order of items makes no
difference.
An example to help further explain the combinations formula:
- How many ways can a group of three students be selected from a class of 21 students?
to answer this we would apply the formula:
catherine,
ReplyDeletegood job of explaining what a combination is and what the formula is, however, it would have been a good addition to the lesson to actually solve the example that you presented at the end. otherwise, good job.
professor little
Catherine I think you did a good job explaining what a combination is and the photo really helped.
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