Problema Solution

A farmer has 100 acres, he will plant corn and wheat. He must plant at least 20 acres of corn. He has 3600 pounds of fertilizer. The corn needs 30 pounds of fertilizer per acre; wheat needs 40 pounds. His profits ate $150/acre of corn and $200/acre of wheat. How much should he plant of each crop to maximize his profit.

Answer provided by our tutors

let


c = acres of corn, c >= 0

w = acres of wheat, w >= 0


a farmer has 100 acres, he will plant corn and wheat


c + w <= 100


he must plant at least 20 acres of corn.


c >= 20


he has 3600 pounds of fertilizer. the corn needs 30 pounds of fertilizer per acre; wheat needs 40 pounds


30c + 40d <= 3600


the profit is determined by the objective function


F(c , w) = 150c + 200w


lets draw the graph of the system of inequalities


w >=0

c + w <= 100

c >= 20

30c + 40w <= 3600


click here to see the graph and find the corner points!


Click to see all the steps



there are 4 corner points and we calculate F(c ,w) for each point to find the maximum value (the biggest value for F):


(20, 0) corner point


F(20, 0) = 150*20 + 200*0 = $3,000


(100, 0) corner point


F(100, 0) = 150*100 + 200*0 = $15,000


(40, 60) corner point


F(40, 60) = 150*40 + 200*60 = $18,000


(20, 75) corner point


F(20, 75) = 150*20 + 200*75 = $18,000


to maximize the profit the farmer should plant 40 acres of corn and 60 acre of wheat or 20 acres of corn and 75 acres of wheat.