document.write( "Question 843940: digits:1,2,3,4,5,6,7,8,9 No repetition is allowed
\n" ); document.write( "a)how many 5 digit numbers are there that exclude 0 and 7
\n" ); document.write( "b) How many of them start with an even number
\n" ); document.write( "c) how many of them start and end with and even number \n" ); document.write( "

Algebra.Com's Answer #508466 by Edwin McCravy(20055) $\"\"$ $\"About$

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digits:1,2,3,4,5,6,7,8,9 No repetition is allowed
\n" ); document.write( "a)how many 5 digit numbers are there that exclude 0 and 7

To exclude 0 and 7 we can only choose\r\n" );
document.write( "from the 8 {1,2,3,4,5,6,8,9}\r\n" );
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document.write( "We can choose the 1st digit 8 ways.\r\n" );
document.write( "We can choose the 2nd digit 7 ways.\r\n" );
document.write( "We can choose the 3rd digit 6 ways.\r\n" );
document.write( "We can choose the 4th digit 5 ways.\r\n" );
document.write( "We can choose the 5th digit 4 ways.\r\n" );
document.write( "\r\n" );
document.write( "8*7*6*5*4 = 6720

b) How many of them start with an even number

We can choose the 1st digit 4 ways.\r\n" );
document.write( "We can choose the 2nd digit 7 ways.\r\n" );
document.write( "We can choose the 3rd digit 6 ways.\r\n" );
document.write( "We can choose the 4th digit 5 ways.\r\n" );
document.write( "We can choose the 5th digit 4 ways.\r\n" );
document.write( "\r\n" );
document.write( "4*7*6*5*4 = 3360

c) how many of them start and end with and even number.

We can choose the 1st digit 4 ways.\r\n" );
document.write( "We can choose the 5th digit 3 ways.\r\n" );
document.write( "We can choose the 2nd digit 6 ways.\r\n" );
document.write( "We can choose the 3rd digit 5 ways.\r\n" );
document.write( "We can choose the 4th digit 4 ways.\r\n" );
document.write( "\r\n" );
document.write( "4*3*6*5*4 = 1440\r\n" );
document.write( "\r\n" );
document.write( "Edwin

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