How much should be blended together of each?

Question

She needs to prepare 120 pounds of blended coffee beans selling for $5.25 per pound. She plans to do this by blending together a high-quality bean costing $6.00 per pound and a cheaper bean at $3.00 per pound. 

Answer 1

Let x be the number of pounds of $6/lb beans. The number of pounds of the $3 beans will be 120 - x.

 

6x + 3(120 - x) = 5.25(120)

 

6x - 3x + 360 = 630

 

3x = 630 - 360 = 270

 

x = 90.

 

90 lbs @ $6 mixed with 30 lbs @ $3.