document.write( "Question 1093789: The total no. Of no. Less than 1000 and divisible by 5 formed with 0,1,2.......9 such that each digit does not occur more than once in each no.is \n" ); document.write( "
Algebra.Com's Answer #708412 by greenestamps(13200)![]() ![]() You can put this solution on YOUR website! If the number is divisible by 5, then the last digit is either 0 or 5. So you have two cases to analyze. \n" ); document.write( "If the last digit is 0, then there are 9 choices for one of the other digits and then 8 choices for the third digit. By the fundamental counting principle, the number of numbers less than 1000, divisible by 5, ending in 0, and containing 3 different digits is 9*8 = 72. \n" ); document.write( "If the last digit is 5, there are still 9 choices for one of the other digits. That is because the problem said \"numbers less than 1000\", not \"3-digit numbers\" -- so the first digit can be 0. And then again there are 8 choices for the last digit, making again 9*8=72 numbers less than 1000, divisible by 5, ending in 5, and containing 3 different digits. \n" ); document.write( "So there are a total of 72+72=144 numbers that are less than 1000, are divisible by 5, and contain 3 different digits. \n" ); document.write( " |