Question 40405
Sliced turkey cost $3.20 per pound.
ground beef cost half as much as the turkey.
Find the price of 7.5 pounds of ground beef.
$3.20 per pound / 2 = $1.60 / pound
(1.60 / lb)*(7.5 lb) = $12
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Let x = kg of Brazilian coffee in mixture
Let y = kg of Turkish coffee in mixture
($5/kg)*(x kg) + ($8/kg)*(y kg) = ($7/ kg)*(300 kg)
x kg + y kg = 300 kg
leaving out the units,
5x + 8y = 2100
 x + y = 300
multiply 2nd equation by 5 and subtract from 1st
5x + 8y = 2100
-5x -5y = -1500
3y = 600
y = 200
x = 300 - y
x = 100
So, 100 kg of the Brazilian coffee should be used
check:
5x + 8y = 2100
5*100 + 8*200 = 2100
500 + 1600 = 2100
2100 = 2100
x + y = 300
100 + 200 = 300
300 = 300
OK