Question

How many three letters code words can be constructed from the first nine letters of the Greek alphabet if no repetition are allowed

Answer 1

504

Explanation:

There are 9 choices for the first letter, 8 choices for the second letter, and 7 choices for the third letter, for a total of 987 = 504 three-letter code words that can be constructed from the first nine letters of the Greek alphabet without repetition.