Physics
Example

Biology
Example

Math
Example

  • Question:
    Think of something you use on a regular basis that requires a code to be entered.
    1. What is the object, that is, how many digits are in the code, and how many choices are there for each?
    2. How many possible codes exist for this object?
    3. How long would it take to break the code trying a new code every second?

  • Answers:
    1. A combination lock...40 digit code in sequntial order...1,099,511,627,776
    2. The code to my electronic diary...4 digits in the code with nine options for each (0-9)...6561 possibilities... That would take 1 hour and 49 minutes.
    3. My bank card...4 numbers get me into my account, so there are 24 possibilites...It would take 1 day or so.
    4. I have a keyless entry on my car...a five digit code and 10 choices for each digit...100,000 possible codes. It would take 1 day, 3 hours and about 45 minutes.