1. Keys pace and modulo operations.
   1. How long does it take (in second) to guarantee to find the correct key if you know a key length is 10 bits? Assume you need one second to verify the correctness of each key.
   2. List five possible numbers for x for the equation x 1 mod 7

2. Assume the rules for generating a password are defined as follows:
   1. Has exactly 4 characters long.
   2. Must have one digit
   3. Must have one up case letter
   4. Must have one of these special characters ~!@#$%^&*()_+
   5. Must have one low case letter

How many possible passwords we can generate? You need to write the formula.