document.write( "Question 806900: You have 4 valves, the first valve took 1 hour to fill a pool, the 2nd valve took 2 hours to fill a pool, the 3rd valve took 3 hours to fill a pool and the fourth valve took 4 hours to fill a pool, if you opened all four valves at the same time, how long would it take to fill the pool? \n" ); document.write( "

Algebra.Com's Answer #486080 by stanbon(75887) $\"\"$ $\"About$

You can put this solution on YOUR website!
You have 4 valves, the first valve took 1 hour to fill a pool, the 2nd valve took 2 hours to fill a pool, the 3rd valve took 3 hours to fill a pool and the fourth valve took 4 hours to fill a pool, if you opened all four valves at the same time, how long would it take to fill the pool?
\n" ); document.write( "-----------
\n" ); document.write( "The valve rates are 1,1/2,1/3,1/4 job/hr
\n" ); document.write( "----------------------
\n" ); document.write( "Together rate = 1/x
\n" ); document.write( "----------------------
\n" ); document.write( "Equation:
\n" ); document.write( "1 + 1/2 + 1/3 + 1/4 = 1/x
\n" ); document.write( "------
\n" ); document.write( "Multiply thru by 12x to get:
\n" ); document.write( "12x + 6x + 4x + 3x = 12
\n" ); document.write( "-------
\n" ); document.write( "25x = 12
\n" ); document.write( "-------
\n" ); document.write( "x = 12/25
\n" ); document.write( "---------
\n" ); document.write( "Time = 12/25 hr = 0.48 hr = 0.48*60 = 28.8 minutes = 28min 28seconds
\n" ); document.write( "=======================================
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H.
\n" ); document.write( "=================== \n" ); document.write( "

\n" );