Using the letters A and B, the following two-letter code words can be formed: AA, AB, BB, BA. Using the letters A, B, and C, how many different three-letter code words can be formed?
No guest! That answer is not 18, and you know it could not possibly be such a large number!
Think of the word as three spaces:
______ _______ _______
Now, each value on top of the spaces is how many options we can choose from:
3 3 3
______ _______ _______
Now, multiply:
3 * 3 * 3
There! 27.
How could that possibly be 18? Last time I checked, 18 did not equal 27...
Still don't believe me? How many more can you find? Oh, so you found another one? Let me hear. ABCDEFGH? Lovely, maybe I forgot about that one....
:)