document.write( "Question 1204315: A three-digit number ABC is divided by the two-digit number AC. The quotient is 11 with no remainder. What is the largest possible number ABC? \n" ); document.write( "
| Algebra.Com's Answer #840491 by math_tutor2020(3817)      You can put this solution on YOUR website! \n" ); document.write( "The three digit number ABC means \n" ); document.write( "A = hundreds digit \n" ); document.write( "B = tens digit \n" ); document.write( "C = units or ones digit\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "ABC is more formally written as 100A+10B+C \n" ); document.write( "AC becomes 10A+C\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Divide those values and we get a quotient of 11 and no remainder.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "(100A+10B+C)/(10A+C) = 11 \n" ); document.write( "100A+10B+C = 11(10A+C) \n" ); document.write( "100A+10B+C = (10+1)(10A+C) \n" ); document.write( "100A+10B+C = 10(10A+C)+1(10A+C) \n" ); document.write( "100A+10B+C = 100A+10C+10A+C \n" ); document.write( "10B+C = 10C+10A+C \n" ); document.write( "10B = 10C+10A \n" ); document.write( "0 = 10A-10B+10C \n" ); document.write( "10(A-B+C) = 0 \n" ); document.write( "A-B+C = 0 \n" ); document.write( "A = B-C\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "To make number ABC as large as possible, we need A as large as possible. \n" ); document.write( "At the same time, we need B to be as large as possible as well. \n" ); document.write( "For unique single digits B and C, B-C maxes out when these digits are as far away from each other as possible, and when B > C. \n" ); document.write( "That happens when B = 9 and C = 0 \n" ); document.write( "So A = B-C = 9-0 = 9\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "But A = 9 and B = 9 overlap. \n" ); document.write( "We assume that A and B are different values. Otherwise the number ABC would be AAC or BBC. \n" ); document.write( "Let's go for B = 9 and C = 1 instead. \n" ); document.write( "A = B-C = 9-1 = 8 \n" ); document.write( "This would allow A,B,C to be different integers.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The number ABC = 891 is the largest possible value so that ABC/AC = 11 without a remainder (i.e. remainder is 0).\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "More specifically, \n" ); document.write( "891/81 = 11\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Answer: 891 \n" ); document.write( " \n" ); document.write( " |