document.write( "Question 249759: How many 4-digit numbers can be formed from the Set A = (0,1,2,3,4,5,6) if there is no repetition. \r
\n" ); document.write( "\n" ); document.write( "My answer is n=6*6*5*4 = 720 4-DIGIT numbers can be formed. \r
\n" ); document.write( "\n" ); document.write( "How many of the numbers in part a are divisible by 5? (You must consider 2 cases.)\r
\n" ); document.write( "\n" ); document.write( "My answer is 720/5=144\r
\n" ); document.write( "\n" ); document.write( "what is the 2 cases I should be looking at?
\n" ); document.write( "Pls help \n" ); document.write( "

Algebra.Com's Answer #181857 by Edwin McCravy(20055) $\"\"$ $\"About$

You can put this solution on YOUR website!
How many 4-digit numbers can be formed from the Set A = (0,1,2,3,4,5,6) if there is no repetition. \r
\n" ); document.write( "\n" ); document.write( "My answer is n=6*6*5*4 = 720 4-DIGIT numbers can be formed.
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document.write( "That's right!\r\n" );
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\n" ); document.write( "How many of the numbers in part a are divisible by 5? (You must consider 2 cases.)\r
\n" ); document.write( "\n" ); document.write( "My answer is 720/5=144
\n" ); document.write( "

\r\n" );
document.write( "That's wrong!\r\n" );
document.write( "

\n" ); document.write( "what is the 2 cases I should be looking at?
\n" ); document.write( "Pls help
\n" ); document.write( "

\r\n" );
document.write( "If a number is divisible by 5 it must end in either a 5 or a 0.\r\n" );
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document.write( "(0,1,2,3,4,5,6)\r\n" );
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document.write( "Choose the fourth digit first.\r\n" );
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document.write( "Case 1.  Choose the fourth digit as 0\r\n" );
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document.write( "That leaves 6 ways to choose the first digit.\r\n" );
document.write( "That leaves 5 ways to choose the second digit.\r\n" );
document.write( "That leaves 4 ways to choose the third digit. \r\n" );
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document.write( "That's 6*5*4 = 120 ways\r\n" );
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document.write( "Case 2.  Choose the fourth digit as 5\r\n" );
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document.write( "That leaves 5 ways to choose the first digit. (It can't be 0)\r\n" );
document.write( "That leaves 5 ways to choose the second digit.\r\n" );
document.write( "That leaves 4 ways to choose the third digit. \r\n" );
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document.write( "That's 5*5*4 = 100 ways \r\n" );
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document.write( "That's a total of 120 + 100 or 220 ways a 4 digit \r\n" );
document.write( "number can end in 0 or 5.\r\n" );
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document.write( "Edwin

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