Which of the following is an example of a combination

B and D are clearly permutation. A and B are selections but arrangement should be done for A where as C only requires selection so C is the combination.

The example which describes combination is:

Combination--

It is a method of choosing or selecting some items from a group of items.

The formula for choosing r items out of a total of n items is given by the formula:

Also, if we are selecting as well as arranging some items from a group of items then that method is known as a method of permutation.

A)

Selecting the best cake and runner up best cake from a cake decorating competition.

In this case we are choosing as well as arranging the best and runner up cake according to their ranks.

Hence, it will be a process of permutation and not combination.

B)

The number of ways 6 people can arrive at a party if no one arrive at the same time.

Again it is a problem of permutation because we have to find the number of ways the people can arrive i.e. arranging people in different orders they may arrive.

C)

Selecting 5 CD's to take with you on a trip from a collection of 30 CD's.

This is a method of combination.

Since we have to select some items from a set of items.

D)

The number of ways triplets can be born.

This is again a process of permutation.

Since there are different order they may come.

in the math equation 8 x 7 = 56, the 8 and the 7 are both factors of 56, since in this lesson we will use square tiles to figure out the factors of a whole find as many different arrays as you can, but follow one important rule: all the rows must have the i can make two rows of nine, so 2 and 9 are both factors of 18.

step-by-step explanation: