Using permutations, it is found that there are 12 ways to pick a sequence of two different letters of the alphabet that appear in the word Crab .
The order in which the letters appears is important, as for example, ab is a difference sequence than ba, hence the permutation formula is used.
Permutation formula:
The number of possible permutations of x elements from a set of n elements is given by:
[tex]P_{(n,x)} = \frac{n!}{(n-x)!}[/tex]
In this problem, 2 letters are picked from a set of 4, hence:
[tex]P_{(4,2)} = \frac{4!}{2!} = 12[/tex]
There are 12 ways to pick a sequence of two different letters of the alphabet that appear in the word Crab .
For more on permutations, you can check https://brainly.com/question/24905801
