document.write( "Question 891345: In the following equation, A, B, C, and D are all positive integers such that A has 4 factors, B has 6 factors, and D has 8 factors. What is the smallest possible sum of A, B, C, and D, if (A×B)/C = D ? \n" ); document.write( "
Algebra.Com's Answer #539677 by richard1234(7193)![]() ![]() You can put this solution on YOUR website! Rearrange to AB = CD\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since D has 8 factors, D can equal p^7 or (p^3)(q^1) or pqr where p, q, r are primes.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Similarly, A is of the form p^3 or pq, and B is of the form p^5 or (p^2)q.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Greedily let D = (2^3)(3) = 24, A = 2*3 = 6, B = (2^2)(3) = 12, so C = 3. A+B+C+D = 6+12+3+24 = 45. \n" ); document.write( " |