SOLUTION: A coffee manufacturer wants to market a new blend of coffee that sells for $3.90 per pound by mixing two coffees that sell for $2.75 and $5 per pound, respectively. what amount of

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Question 1014810: A coffee manufacturer wants to market a new blend of coffee that sells for $3.90 per pound by mixing two coffees that sell for $2.75 and $5 per pound, respectively. what amount of each coffee should be blended to obtain the desired mixture? (hint: Assume that the total weight of the desired blend is 100 pounds)
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Let +a+ = pounds of $2.75/ lb coffee needed
Let +b+ = pounds of $5.00/ lb coffee needed
Assume total of 100 pounds of blend
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(1) +a+%2B+b+=+100+
(2) +%28+2.75a+%2B+5b+%29+%2F+100+=+3.9+
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(2) +2.75a+%2B+5b+=+390+
(2) +275a+%2B+500b+=+39000+
(2) +11a+%2B+20b+=+1560+
Multiply both sides of (1) by +11+
and subtract (1) from (2)
(2) +11a+%2B+20b+=+1560+
(1) +-11a+-+11b+=+-1100+
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+9b+=+460+
+b+=+51.11+
and
(1) +a+%2B+b+=+100+
(1) +a+=+48.89+
48.89 pounds of $2.75/ lb coffee are needed
51.11 pounds of $5.00/ lb coffee are needed
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check:
(2) +%28+2.75a+%2B+5b+%29+%2F+100+=+3.9+
(2) +%28+2.75%2A48.89+%2B+5%2A51.11+%29+%2F+100+=+3.9+
(2) +%28+134.45+%2B+255.55+%29+%2F+100+=+3.9+
(2) +390+=+390+
OK