How many different characters can the international code

[Guest]

Before the invention of the telephone, Samuel Morse developed an efficient sytem for sending messages as a series of dots and dashes (short or long pulses). International code, a modified version of Morse code is still widely used.

How many different characters can the international code represent with one to four pulses?

I dont get this at all. How would you do this?
I thought it was going to be like (26)(26)(26)(26) but, I dunno, I dont get the dots and dashes..

Thanks

 

[soroban]

Hello, Anna!

Before the invention of the telephone, Samuel Morse developed an efficient sytem
for sending messages as a series of dots and dashes (short or long pulses).
International code, a modified version of Morse code is still widely used.

How many different characters can the code represent with one to four pulses?

Don't think of "dots and dashes" . . . Think of the two sounds: "dit" and "dah".
. . That's the sound you hear when code is being sent.

Some examples: \(\displaystyle \;\begin{array}{ccc}B&=&\text{dah-dit-dit-dit}\\R&=&\text{dit-dah-dit}\\Q&=&\text{dah-dah-dit-dah}\end{array}\)

\(\displaystyle \begin{array}{ccc}\text{One pulse: } & 2^1 & = & 2\text{ ways}\\
\text{Two pulses: } & 2^2 & = & 4\text{ ways} \\
\text{Three pulses: } & 2^3 & = & 8\text{ ways} \\
\text{Four pulses: } & 2^4 & = & 16\text{ ways} \end{array}\)

A total of: \(\displaystyle \,2\,+\,4\,+\,8\,+\,16\:=\:30\) characters could be represented.

 

[Guest]

ok, If I understand that correctly, for this question:

How many pulses would be necessary to represent the 72 letters of the Cambodian alphabet using a system like Morse code?

Would you set it up like : 2^n= 72?

The answer is suppose to be 6..