document.write( "Question 1173513: A metalworker has a metal alloy that is 20​% copper and another alloy that is 70​% copper. How many kilograms of each alloy should the metalworker combine to create 80kg of a 60​% copper​ alloy \n" ); document.write( "
Algebra.Com's Answer #798727 by greenestamps(13200)\"\" \"About 
You can put this solution on YOUR website!


\n" ); document.write( "If a formal algebraic solution is not required, try this quick and easy method for solving 2-part \"mixture\" problems like this:

\n" ); document.write( "You are mixing 20% copper with 70% copper to get 60% copper.
\n" ); document.write( "60% is 40/50 = 4/5 of the way from 20% to 70%. (picture the three percentages on a number line, if it helps....)
\n" ); document.write( "That means 4/5 of the mixture is the higher percentage alloy.

\n" ); document.write( "ANSWER: 4/5 of 80kg, or 64kg, of 70% copper; the other 16kg of 20% copper.

\n" ); document.write( "CHECK:
\n" ); document.write( ".70(64)+.20(16) = 44.8+3.2 = 48
\n" ); document.write( ".60(80) = 48

\n" ); document.write( "
\n" ); document.write( "
\n" );