document.write( "Question 397865: The radiator in a car is filled with a solution of 70% antifreeze and 30% water. The manufacturer of the antifreeze suggests that, for summer driving, optimal cooling of the engine is obtained with only 60% antifreeze. If the capacity of the radiator is 3.5 L, how much coolant should be drained and replaced with water to reduce the antifreeze concentration to the recommended level? \n" ); document.write( "
Algebra.Com's Answer #281888 by ankor@dixie-net.com(22740)\"\" \"About 
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The radiator in a car is filled with a solution of 70% antifreeze and 30% water.
\n" ); document.write( " The manufacturer of the antifreeze suggests that, for summer driving, optimal
\n" ); document.write( " cooling of the engine is obtained with only 60% antifreeze.
\n" ); document.write( " If the capacity of the radiator is 3.5 L, how much coolant should be drained
\n" ); document.write( " and replaced with water to reduce the antifreeze concentration to the recommended level?
\n" ); document.write( ":
\n" ); document.write( "let x = amt to be removed, also = the amt of water to be added
\n" ); document.write( ":
\n" ); document.write( "We can do this equation using per cent water
\n" ); document.write( ":
\n" ); document.write( "70% antifreeze is 30% water
\n" ); document.write( "60% antifreeze is 40% water
\n" ); document.write( ":
\n" ); document.write( ".30(3.5-x) + x = .40(3.5)
\n" ); document.write( "1.05 - .3x + x = 1.36
\n" ); document.write( "-.3x + x = 1.26 - 1.05
\n" ); document.write( ".7x = .31
\n" ); document.write( "x = \".31%2F.7\"
\n" ); document.write( "x ~ .443 liters removed and .443 liters of water added
\n" ); document.write( ";
\n" ); document.write( ":
\n" ); document.write( "Check solution using percent antifreeze
\n" ); document.write( ".7(3.5-.443) = .6(3.5)
\n" ); document.write( ".7(3.057) = 2.1
\n" ); document.write( "2.14 ~ 2.10\r
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