document.write( "Question 30470: How many ordered triples (X,Y,Z) of postive intgers satisfy X*Y*Z=4000? \n" ); document.write( "
Algebra.Com's Answer #17122 by khwang(438)![]() ![]() ![]() You can put this solution on YOUR website! X*Y*Z=4000 = 4*(2*5)^3 = 2^5* 5^3.\r \n" ); document.write( "\n" ); document.write( " so X, Y, Z are in the form 2^i * 5^j (X= 2^i1 * 5^j1,.. \n" ); document.write( " with i1+i2+i3 = 5 and j1+j2+j3 = 3.\r \n" ); document.write( "\n" ); document.write( " there are C(3+5-1, 5) = C(7,5) = 21 possible i's(why?) \n" ); document.write( " and C(3+3-1, 3) = C(5,3) = 10 possible j's\r \n" ); document.write( "\n" ); document.write( " Totally, there are 21*10 = 21 possible ordered triples (X,Y,Z).\r \n" ); document.write( "\n" ); document.write( " Try X*Y = 2^3* 5^2\r \n" ); document.write( "\n" ); document.write( " Kenny\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |