document.write( "Question 858513: how many 3-digit numbers are made of 3 different even digits and are divisible by 5? \n" ); document.write( "
Algebra.Com's Answer #517236 by Edwin McCravy(20055)![]() ![]() You can put this solution on YOUR website! \r\n" ); document.write( "The even digits are {0,2,4,6,8}.\r\n" ); document.write( "For an integer to be divisible by 5 it must either end in 0 or 5.\r\n" ); document.write( "5 isn't an even digit, so it can only end in 0.\r\n" ); document.write( "\r\n" ); document.write( "We can choose the last digit only 1 way, 0.\r\n" ); document.write( "We can choose the first digit any of the 4 remaining ways: {2,4,6,8}.\r\n" ); document.write( "We can choose the second digit 3 ways, any of the 3 remaining even \r\n" ); document.write( "digits that weren't chosen for the first or third digit.\r\n" ); document.write( "\r\n" ); document.write( "That's 1 = 12. Here they all are: \r\n" ); document.write( "\r\n" ); document.write( " 1. 240\r\n" ); document.write( " 2. 260\r\n" ); document.write( " 3. 280\r\n" ); document.write( " 4. 420\r\n" ); document.write( " 5. 460\r\n" ); document.write( " 6. 480\r\n" ); document.write( " 7. 620\r\n" ); document.write( " 8. 640\r\n" ); document.write( " 9. 680\r\n" ); document.write( "10. 820\r\n" ); document.write( "11. 840\r\n" ); document.write( "12. 860\r\n" ); document.write( "\r\n" ); document.write( "Edwin\n" ); document.write( " |