document.write( "Question 36176: Suppose W varies directly as x and y and inversely as Z, and W=48 when X=2, Y=8 and Z=12. Find W when X=12, Y=6 and Z=24. \n" ); document.write( "

Algebra.Com's Answer #22191 by kev82(151) $\"\"$ $\"About$

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Hi,\r
\n" ); document.write( "\n" ); document.write( "X has gone from 2 to 12, so it has multiplied by 6.\r
\n" ); document.write( "\n" ); document.write( "Y has gone from 8 to 6 so has been multiplied by 3/4\r
\n" ); document.write( "\n" ); document.write( "Z has gone from 12 to 24 so has multipled by 2.\r
\n" ); document.write( "\n" ); document.write( "W varies directly in X and Y, so whatever we do to them is done to W. But it varies inversly in Z so whatever we do to Z, we do the opposite. Therefore W has changed by 6 * 3/4 * 1/2 = 2.25. So the new value for W is 48 * 2.25 = 108.\r
\n" ); document.write( "\n" ); document.write( "The other way to do this is say $\"W=kXY%2FZ\"$ and use the original data to find $\"k\"$ then put the new values in. If you try that you should get $\"k\"$ as 36.\r
\n" ); document.write( "\n" ); document.write( "Hope that helps,\r
\n" ); document.write( "\n" ); document.write( "Kev. \n" ); document.write( "

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