A coffee merchant combines coffee that costs $7 per pound with coffee that costs $3.60 per pound. How many pounds of each should be used to make 26 lb of a blend costing $6.15 per pound?
First you want to set up two equations. Then substitute one into the other to solve:
Let x be pounds of $7 coffee and y be pounds of $3.60 coffee which equals the total pounds of coffee:
The total cost of blended coffee is calculated by adding the total cost of the two different coffees together:
To solve for one variables use the substitution method:
So it takes 19.5lb of the $7/lb coffee and 6.5lb of the $3.50/lb coffee to make 26lb of the blended coffee at $6.15/lb.