document.write( "Question 412809: Morse code for the alphabet consists of dots and dashes. Each symbol contains between 1 and 4 dots and dashes. How many different symbols can be made?\r
\n" ); document.write( "\n" ); document.write( "I have tried writing all possibilities (too many). Also tried using 4!2!, but don't think that is right. \r
\n" ); document.write( "\n" ); document.write( "Thank you in advance for your help! \n" ); document.write( "
Algebra.Com's Answer #289883 by richard1234(7193)\"\" \"About 
You can put this solution on YOUR website!
No need to write all the possibilities. Do it case by case (it's easier to count it this way)\r
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\n" ); document.write( "\n" ); document.write( "Case 1: A letter consists of one \"character.\"\r
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\n" ); document.write( "\n" ); document.write( "This leaves two possibilities, so 2.\r
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\n" ); document.write( "\n" ); document.write( "Case 2: A letter consists of two characters.\r
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\n" ); document.write( "\n" ); document.write( "There are two possibilities for each position, so 4.\r
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\n" ); document.write( "\n" ); document.write( "The other cases (3 and 4 characters) imply 8 and 16 possibilities (by using a simple induction argument), so the total number is 2 + 4 + 8 + 16 = 30. \n" ); document.write( "
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