Answer:
The example which describes combination is:
- Selecting 5 CD's to take with you on a trip from a collection of 30 CD's.
Step-by-step explanation:
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:
[tex]n_C_r=\dfrac{n!}{r!\times (n-r)!}[/tex]
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.
