Answer: e) [tex]27(26^5)[/tex]
Step-by-step explanation:
Given : All of the stocks on the over-the-counter market are designated by either a 4-letter or a 5-letter code that is created by using the 26 letters of the alphabet.
The number of ways to make a 4-letter code ( If repetition of letters is allowed) = [tex]26\times26\times26\times26=(26)^4[/tex]
Similarly, The number of ways to make a 5-letter code =
[tex]26\times26\times26\times26\times26=(26)^5[/tex]
Now, the combined number of ways to make either a 4-letter or a 5-letter code :-
[tex](26)^4+(26)^5=(26)^4(1+26)=(26)^4(27)=27(26)^4[/tex]
Hence, the correct answer is e) [tex]27(26^5)[/tex].
