3. Some ten-year-olds are experimenting with secret codes. Aisha's favorite code involves replacing each letter with the one two letters later, so A is replaced with C, B with D, Y with A, and Z with B. Meanwhile, Tim prefers to replace letters with their position in the alphabet: 1 for A, 2 for B, and so on. Suppose Aisha encodes the word "spam" with her code and Tim encodes the result with his code. a) What will the outcome be? b) Describe this scenario in terms of functions and their composition. c) Suppose Aisha's code is defined only for letters, not numbers. Could the kids apply Tim's code and then Aisha's code to a message? Explain your answer in terms of domains and codomains.