document.write( "Question 495346: Soybean meal is 16% protein, cornmeal is 8% protein. How many pounds of each should be mixed together in order to get 320-lb mixture that is 11% protein? \n" ); document.write( "

Algebra.Com's Answer #336071 by oberobic(2304) $\"\"$ $\"About$

You can put this solution on YOUR website!
For mixture problems you need to keep track of how much \"pure\" stuff you need.
\n" ); document.write( "The result is supposed to be 320 lb that is 11% protein.
\n" ); document.write( "That means you need to have 35.2 lb of pure protein. The rest is not protein.
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\n" ); document.write( "To get to 11% you need to mix soybean meal that is 16% protein with cornmeal that is 8% protein.
\n" ); document.write( "Let S be the weight of soybean meal.
\n" ); document.write( "Logically 320 minus S will be the weight of the cornmeal.
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\n" ); document.write( "So, looking back at how much pure stuff we need, we can calculate:
\n" ); document.write( ".16*S + .08*(320 -S) = 35.2
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\n" ); document.write( "Multiply both sides by 100 to eliminate the decimals.
\n" ); document.write( "16S + 8(320 -S) = 3520
\n" ); document.write( "16S + 2560 -8S = 3520
\n" ); document.write( "8S = 3520 - 2560
\n" ); document.write( "8S = 960
\n" ); document.write( "S = 120 lb of soybean meal
\n" ); document.write( "that means you have 320 - 120 = 200 lb of cornmeal.
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\n" ); document.write( "Always check your answer.
\n" ); document.write( "200 lb of cornmeal has 8% protein, which = 16 lb.
\n" ); document.write( "120 lb of soybean meal has 16% protein, which = 19.2 lb
\n" ); document.write( "16 + 19.2 = 35.2 lb of protein
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\n" ); document.write( "Answer:
\n" ); document.write( "Add 200 lb of cornmeal and 120 lb of soybean meal to have 320 lb of mixture with 11% protein.
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\n" ); document.write( "Done. \n" ); document.write( "

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