Floral Coffee sells out a custom blend of Kona and Hazelnut

Floral Coffee sells out a custom blend of Kona and Hazelnut coffees. Kona sells for $13.00 a pound and Hazelnut sells for $7.50 a pound. How much Kona coffee must be added to 10 pounds of Hazelnut coffee to make a blend worth $11.00 a pound?

please show steps

Solution

Kona sells for $13.00 a pound and

Hazelnut sells for $7.50 a pound

Let x pounds of Kona coffee is added to Hazelnut:

Total coffee = ( 10+x) at $11.00 a pound

11(10+x) = 10*7.50 +x*13

110 +11x = 75 +13x

11x - 13x = 75-110

-2x = -35

x = 35/2 = 17.5 pounds of Kona coffee is added