document.write( "Question 1111274: There is a problem I don't understand.\r
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\n" ); document.write( "\n" ); document.write( "The first year the state of Pennsylvania issued railroad memorial license plates, the plates had a picture of a stream engine followed by four digits. Assuming that repetitions are allowed, how many railroad memorial plates could be issued.\r
\n" ); document.write( "\n" ); document.write( "the solution has four \"10s\" that equal 10,000and I don't understand how they got that answer. how did they come up with the number 10. I just need someone to shed some light on this for me.\r
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Algebra.Com's Answer #726263 by ikleyn(52832) $\"\"$ $\"About$

You can put this solution on YOUR website!
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document.write( "The digits are 0, 1, 2, 3, 4, 5, 6, 7, 8, and 9 - in all, there are 10 digits.\r\n" );
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document.write( "Any of 10 digit can be placed on the most-left position.  It gives 10 options.\r\n" );
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document.write( "Any of 10 digit can be placed on the next      position.  It gives 10 options.\r\n" );
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document.write( "Any of 10 digit can be placed on the third     position.  It gives 10 options.\r\n" );
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document.write( "Any of 10 digit can be placed on the fourth    position.  It gives 10 options.\r\n" );
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document.write( "All these options are INDEPENDENT. You can combine them in ANY way.\r\n" );
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document.write( "Therefore, there are   possible combinations of 10 digits in 4-digit words.\r\n" );
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\n" ); document.write( "\n" ); document.write( "It is the explanation you wanted.\r
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\n" ); document.write( "It is THE STANDARD explanation/solution for such problems.\r
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\n" ); document.write( "\n" ); document.write( "By the way, this fact is STRICTLY PARALLEL to the fact that there are $\"10%5E4\"$ integer numbers from 0 = 0000 to 9999 inclusively.\r
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