Answer:
160 pounds at 2.70
240 pounds at 3.20
Step-by-step explanation:
Let x be the pounds and 2.70 per pound
400-x is the pounds and 3.20 per pound
there will be 400 pounds and 3.00 per pound
2.70 x + (400-x) *3.20 = 400 *3
Distribute
2.70x +1280-3.20x = 1200
Combine like terms
-.5x +1280 = 1200
Subtract 1280 from each side
-.5x = -80
Divide each side by -.5
x = -80/-/5
x =160
160 pounds at 2.70
400-160 = 240 pounds at 3.20