document.write( "Question 347351: John by himself can paint 4 rooms in 10 hrs. if he hires Mark to help, they can do the same job together in 6 hrs. if he lets Mark work alone, how long will it take for Mark to paint 4 rooms? \n" ); document.write( "
Algebra.Com's Answer #248370 by stanbon(75887)![]() ![]() ![]() You can put this solution on YOUR website! John by himself can paint 4 rooms in 10 hrs. if he hires Mark to help, they can do the same job together in 6 hrs. if he lets Mark work alone, how long will it take for Mark to paint 4 rooms? \n" ); document.write( "------- \n" ); document.write( "John DATA: \n" ); document.write( "time = 10 hrs/job ; rate = 1/10 job/hr \n" ); document.write( "----------------------- \n" ); document.write( "Together DATA: \n" ); document.write( "time = 6 hrs/job ; rate = 1/6 job/hr \n" ); document.write( "----------------------- \n" ); document.write( "Mark DATA: \n" ); document.write( "time = x hrs/job ; rte = 1/x job/hr. \n" ); document.write( "======================================= \n" ); document.write( "Equation: \n" ); document.write( "rate + rate = together rate \n" ); document.write( "1/10 + 1/x = 1/6 \n" ); document.write( "Multiply thru by 30x to get: \n" ); document.write( "3x + 30 = 5x \n" ); document.write( "2x = 30 \n" ); document.write( "x = 15 hrs (time for Mark to do the job alone) \n" ); document.write( "======================== \n" ); document.write( "Cheers, \n" ); document.write( "Stan H. \n" ); document.write( " \n" ); document.write( " |