Question

ow many 3-letters code can be formed with the letters A, B, C, if each letter can be repeated any number of times in the code?

Answer 1

27.

A sample of your result will be _ _ _ and any the candidate for the first _ are all 3, for the second are all 3 and for the third are as well are all 3. This is because repetition is allowed. Thus 3*3*3 =27