A dairy farmer wants to mix a 55% protein supplement and a standard 25% protein ration to make 1500 pounds of a high-grade 35% protein ration. How many pounds of each should he use?

He used 55% protein 500 pounds and 25% protein 1000 pounds

Step-by-step explanation:

x pounds of 55% contains x * 0.55 pounds of pure protein

y pounds of 25% contains x * 0.25 pounds of pure protein

1500 pounds of 35% contains 1500 * 0.35 = 525 pounds of pure protein

x + y = 1500 ... (1)

0.55 x + 0.25 y = 525 ... (2)

0.25 times both sides of (1)

0.25 x + 0.25 y = 1500 * 0.25 = 375 ... (3)

(2) - (3) 0.3 x = 150 ... divide 0.3 on both sides

x = 500

y = 1500 - 500 = 1000