Answer:
The total number of possible outcomes if the code has 3 letters is 64
Step-by-step explanation:
The keypad has only the letters A-D, that is, A,B,C,D.
To calculate the total number of possible outcomes if the code has 3 letters,
let these spaces represent the code _ _ _
For the first space, there are 4 possibilities (since we have 4 letters)
For the second space, we also have 4 possibilities (since there is no restriction on repetition)
Also, we have 4 possibilities for the last space.
Hence, the total number of possible outcomes if the code has 3 letters is 4×4×4 = 4³ = 64.