document.write( "Question 327711: How much 20% acid solution and 80% acid solution should be combined to obtain 100 liters of 62% acid solution? \n" ); document.write( "

Algebra.Com's Answer #234717 by josmiceli(19441) $\"\"$ $\"About$

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Let $\"a\"$ = liters of 20% acid solution needed
\n" ); document.write( "Let $\"b\"$ = liters of 80% acid solution needed
\n" ); document.write( "given:
\n" ); document.write( " $\"a+%2B+b+=+100\"$ liters
\n" ); document.write( " $\"20a+%2B+20b+=+2000\"$ liters
\n" ); document.write( "--------------------------
\n" ); document.write( "acid in final solution:
\n" ); document.write( " $\".2a+%2B+.8b+=+.62%2A100\"$
\n" ); document.write( " $\"20a+%2B+80b+=+6200\"$
\n" ); document.write( " $\"-20a+-+20b+=+-2000\"$ subtract
\n" ); document.write( " $\"60b+=+4200\"$
\n" ); document.write( " $\"b+=+70\"$ liters
\n" ); document.write( "and, since
\n" ); document.write( " $\"a+%2B+b+=+100\"$
\n" ); document.write( " $\"a+=+30\"$ liters
\n" ); document.write( "30 liters of 20% solution and
\n" ); document.write( "70 liters of 80% solution are needed
\n" ); document.write( "check:
\n" ); document.write( " $\".2a+%2B+.8b+=+.62%2A100\"$
\n" ); document.write( " $\".2%2A30+%2B+.8%2A70+=+62\"$
\n" ); document.write( " $\"6+%2B+56+=+62\"$
\n" ); document.write( " $\"62+=+62\"$
\n" ); document.write( "OK\r
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "

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