document.write( "Question 255523: how many even three digit numbers are there such that the sum of the tens and unit digits is 13? \n" ); document.write( "
Algebra.Com's Answer #187965 by Edwin McCravy(20055)![]() ![]() You can put this solution on YOUR website! \r\n" ); document.write( "The last digit must be even, and only 3 of the even digits are such that\r\n" ); document.write( "you can add another digit to them and get 13. These are 4, 6 and 8, because\r\n" ); document.write( "0 and 2 are too small.\r\n" ); document.write( "\r\n" ); document.write( "For each of the 3 ways we can choose a units digit, we can choose a tens digit\r\n" ); document.write( "only 1 way, and that's whatever digit we must add to the units digit to get\r\n" ); document.write( "13. For each of those, there are 9 ways to choose a hundreds digit, 1-9,\r\n" ); document.write( "so as to have a three-digit number.\r\n" ); document.write( "\r\n" ); document.write( "That's 3x1x9 = 27 ways. Here they all are:\r\n" ); document.write( " \r\n" ); document.write( "1. 158\r\n" ); document.write( "2. 176\r\n" ); document.write( "3. 194\r\n" ); document.write( "4. 258\r\n" ); document.write( "5. 276\r\n" ); document.write( "6. 294\r\n" ); document.write( "7. 358\r\n" ); document.write( "8. 376\r\n" ); document.write( "9. 394\r\n" ); document.write( "10. 458\r\n" ); document.write( "11. 476\r\n" ); document.write( "12. 494\r\n" ); document.write( "13. 558\r\n" ); document.write( "14. 576\r\n" ); document.write( "15. 594\r\n" ); document.write( "16. 658\r\n" ); document.write( "17. 676\r\n" ); document.write( "18. 694\r\n" ); document.write( "19. 758\r\n" ); document.write( "20. 776\r\n" ); document.write( "21. 794\r\n" ); document.write( "22. 858\r\n" ); document.write( "23. 876\r\n" ); document.write( "24. 894\r\n" ); document.write( "25. 958\r\n" ); document.write( "26. 976\r\n" ); document.write( "27. 994\r\n" ); document.write( "\r\n" ); document.write( "Edwin\n" ); document.write( " |