Applying the Combinations Formula to Exam Questions скачать в хорошем качестве

Applying the Combinations Formula to Exam Questions

Applying the Combinations Formula to Exam Questions a) Without the assistance of a calculator, evaluate 6C4 b) Show that nC1=n and nC2=n(n-1)/2 In mathematics, a combination is a selection of items from a collection, such that (unlike permutations) the order of selection does not matter. For example, given three fruits, say an apple, an orange and a pear, there are three combinations of two that can be drawn from this set: an apple and a pear; an apple and an orange; or a pear and an orange. More formally, a k-combination of a set S is a subset of k distinct elements of S. If the set has n elements, the number of k-combinations is equal to the binomial coefficient. Combinations refer to the combination of n things taken k at a time without repetition. To refer to combinations in which repetition is allowed, the terms k-selection, k-multiset, or k-combination with repetition are often used. If, in the above example, it were possible to have two of any one kind of fruit there would be 3 more 2-selections: one with two apples, one with two oranges, and one with two pears. If you would like to contact me my email is harry.w.walden@gmail.com Hope the video helps :) Harold