document.write( "Question 1208723: Ruth has a beaker containing a solution of $800$ mL of acid and $200$ mL of water. She thinks the solution is a little strong, so she drains $300$ mL from the beaker, adds $300$ mL of water, and stirs the solution. Ruth thinks the solution is still too strong, so again she drains $400$ mL from the beaker, and adds $400$ mL of water. Ruth again thinks the solution is still too strong, so again she drains $100$ mL from the beaker, and adds $100$ mL of water. How many mL of water are now in the beaker? \n" ); document.write( "
Algebra.Com's Answer #847130 by Edwin McCravy(20055)![]() ![]() You can put this solution on YOUR website! \r\n" ); document.write( "First, I'll copy and paste your problem here so I can delete those \"$\" dollar\r\n" ); document.write( "marks around every number. They confuse me. We didn't do that where I came\r\n" ); document.write( "from. J\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Ruth has a beaker containing a solution of 800 mL of acid and 200 mL of water.\r\n" ); document.write( "She thinks the solution is a little strong, so she drains 300 mL from the\r\n" ); document.write( "beaker, adds 300 mL of water, and stirs the solution. Ruth thinks the solution\r\n" ); document.write( "is still too strong, so again she drains 400 mL from the beaker, and adds 400 mL\r\n" ); document.write( "of water. Ruth again thinks the solution is still too strong, so again she\r\n" ); document.write( "drains 100 mL from the beaker, and adds 100 mL of water. How many mL of water\r\n" ); document.write( "are now in the beaker?\r\n" ); document.write( "\r\n" ); document.write( "I'll keep track of the liquid, acid, water, % acid, and % water, because in\r\n" ); document.write( "other problems like this you might be asked different amounts and percentages.\r\n" ); document.write( " \r\n" ); document.write( "Ruth has a beaker containing a solution of 800 mL of acid and 200 mL of water. \r\n" ); document.write( "\r\n" ); document.write( " liquid = 800+200 = 1000 mL\r\n" ); document.write( " acid = 800 mL\r\n" ); document.write( " water = 200 mL\r\n" ); document.write( " % acid = 800/1000 = 0.8 = 80%\r\n" ); document.write( "% water = 200/1000 = 0.2 = 20% \r\n" ); document.write( "\r\n" ); document.write( "She thinks the solution is a little strong, so she drains 300 mL from the beaker, \r\n" ); document.write( "\r\n" ); document.write( " liquid = 1000-300 = 700 mL\r\n" ); document.write( " acid = (0.8)(700) = 560 mL\r\n" ); document.write( " water = (0.2)(700) = 140 mL\r\n" ); document.write( " % acid = 80%\r\n" ); document.write( "% water = 20% \r\n" ); document.write( "\r\n" ); document.write( "adds 300 mL of water, and stirs the solution. \r\n" ); document.write( "\r\n" ); document.write( " liquid = 700+300 = 1000 mL\r\n" ); document.write( " acid = 560 mL\r\n" ); document.write( " water = 140+300 = 440 mL\r\n" ); document.write( " % acid = 560/1000 = 0.56 = 56%\r\n" ); document.write( "% water = 440/1000 = 0.44 = 44% \r\n" ); document.write( "\r\n" ); document.write( "Ruth thinks the solution is still too strong, so again she drains 400 mL from the beaker, \r\n" ); document.write( "\r\n" ); document.write( " liquid = 1000-400 = 600 mL\r\n" ); document.write( " acid = (600)(0.56) = 336 mL\r\n" ); document.write( " water = (600)(0.44) = 264 mL\r\n" ); document.write( " % acid = 56%\r\n" ); document.write( "% water = 44% \r\n" ); document.write( "\r\n" ); document.write( "and adds 400 mL of water. \r\n" ); document.write( "\r\n" ); document.write( " liquid = 600+400=1000 mL\r\n" ); document.write( " acid = 336 mL\r\n" ); document.write( " water = 264+400=664 mL\r\n" ); document.write( " % acid = 336/1000=33.6% \r\n" ); document.write( "% water = 664/1000=66.4% \r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "Ruth again thinks the solution is still too strong, so again she drains 100 mL from the beaker, \r\n" ); document.write( "\r\n" ); document.write( " liquid = 1000-100=900 mL\r\n" ); document.write( " acid = (900)(0.336) = 302.4 mL\r\n" ); document.write( " water = 664-100=564 mL\r\n" ); document.write( " % acid = 33.6% \r\n" ); document.write( "% water = 66.4% \r\n" ); document.write( "\r\n" ); document.write( "and adds 100 mL of water. \r\n" ); document.write( "\r\n" ); document.write( " liquid = 900+100=1000 mL \r\n" ); document.write( " acid = 302.4 mL\r\n" ); document.write( " water = 564+100=664 mL\r\n" ); document.write( " % acid = 302.4/1000 0.3024=30.24% \r\n" ); document.write( "% water = 664/1000 = 0.664 = 66.4% \r\n" ); document.write( "\r\n" ); document.write( "How many mL of water are now in the beaker? \r\n" ); document.write( "\r\n" ); document.write( "664 mL <-- ANSWER\r\n" ); document.write( "\r\n" ); document.write( "Edwin\n" ); document.write( " |