strange permutations question?
How, step by step please, can the following question be answered?
"Suppose you are designing a remote control that uses short, medium, or long pulses of infrared light to send control signals to a device. How many different control codes can you define using
a) three pulses?
b) one, two, or three pulses?"
Thank you guys so much in advance!
- Mike TLv 79 years agoFavorite Answer
a) Knowing that each signal consists of 3 pulse, there are 3 possible values (Short, Medium, and Long) for each of the pulses. Total possibilities: 3 * 3 * 3 = 27
b) This problem is a little more interesting because now the receiver needs to be able to tell when on signal stops and the next one starts. So what we do is for any sequence less than 3 pulses, we'll select a specific pulse to be the "stop" marker. For this, I'll choose Long.