Hexadecimal numbers use 16 hex-digits (\{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A, B, C, D, E, F\}) to represent data. 1. How many 2 hex-digit numbers begin with either E or F ? 2. How many 2 hex-digit numbers end with a number 0 to 9 ? 3. How many 2 hex-digit numbers begin with a letter (A to F) and end with a number (0 to 9)? 4. How many 2 hex-digit numbers begin with a letter (A to F ) or end with a number (0 to 9)?