document.write( "Question 770199: 1.How many ways 3-digit odd number can be formed by using the digit 1 to 9 when repetition is not allowed.?\r
\n" ); document.write( "\n" ); document.write( "2.how many numbers are there between 200 to 300 in which all of the digits are distint.?\r
\n" ); document.write( "\n" ); document.write( "3.find the number of ways in which 5 boys and 4 girls can be seated in a row so that no two girls are together.? \n" ); document.write( "

Algebra.Com's Answer #469508 by Edwin McCravy(20056) $\"\"$ $\"About$

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1.How many ways 3-digit odd number can be formed by using the digit 1 to 9 when repetition is not allowed.?
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document.write( "Choose the first digit any of 9 ways.\r\n" );
document.write( "Choose the second digit any of the 8 remaining ways.\r\n" );
document.write( "Choose the third digit any of the 7 remaining ways.\r\n" );
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document.write( "Answer = 9·8·7 = 504\r\n" );
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\n" ); document.write( " 2.how many numbers are there between 200 to 300 in which all of the digits are distint.?
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document.write( "Choose the fisrt digit as 2, that's 1 way.\r\n" );
document.write( "Choose the second digit any of the 8 remaining ways.\r\n" );
document.write( "Choose the third digit any of the 7 remaining ways.\r\n" );
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document.write( "Answer 1·8·7 = 56\r\n" );
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\n" ); document.write( " 3.find the number of ways in which 5 boys and 4 girls can be seated
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document.write( "There are 15 ways they can be arranged\r\n" );
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document.write( "1. BBGBGBGBG\r\n" );
document.write( "2. BGBBGBGBG\r\n" );
document.write( "3. BGBGBBGBG\r\n" );
document.write( "4. BGBGBGBBG\r\n" );
document.write( "5. BGBGBGBGB\r\n" );
document.write( "6. GBBBGBGBG\r\n" );
document.write( "7. GBBGBBGBG\r\n" );
document.write( "8. GBBGBGBBG\r\n" );
document.write( "9. GBBGBGBGB\r\n" );
document.write( "10. GBGBBBGBG\r\n" );
document.write( "11. GBGBBGBBG\r\n" );
document.write( "12. GBGBBGBGB\r\n" );
document.write( "13. GBGBGBBBG\r\n" );
document.write( "14. GBGBGBBGB\r\n" );
document.write( "15. GBGBGBGBB\r\n" );
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document.write( "For each of those 15 ways there are 5! ways to seat the boys,\r\n" );
document.write( "and 4! ways to seat the girls.\r\n" );
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document.write( "Number of ways = 15·5!·4! = 15·120·24 = 43,200 ways.\r\n" );
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document.write( "Edwin \n" );
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