# Worksheet: Optimization with Linear Programming

In this worksheet, we will practice using linear programming to find the optimum solution for a given real-life situation.

Q1:

A farmer can improve the quality of his produce if he uses at least 18 units of nitrogen-based compounds and at least 6 units of phosphate compounds. He can use two types of fertilizers: A and B. The cost and contents of each fertilizer are shown in the table.

The Fertilizer Number of Units of Nitrogen-Based Compounds per Kilogram Number of Units of Phosphate Compounds per Kilogram Cost for each Kilogram (LE)
A 3 2 170
B 6 1 120

Given that the graph represents the constraints in this situation, find the lowest cost the farmer can pay for fertilizer while providing sufficient amounts of both compounds.

Q2:

While on a trip you decide to buy cashews and pistachios. Given that you want to spend less than 204 LE, the figure below illustrates the relation between the number of kilograms of cashews and pistachios you can buy. Determine the price of a kilogram of cashews and a kilogram of pistachios.

• Acashews = 4 LE, pistachios = 3 LE
• Bcashews = 136 LE, pistachios = 153 LE
• Ccashews = 51 LE, pistachios = 68 LE
• Dcashews = 68 LE, pistachios = 51 LE
• Ecashews = 3 LE, pistachios = 4 LE

Q3:

A factory produces two types of iron desks: Type A and Type B. One worker builds the desks and another sprays them. It takes the first worker 3.5 hours to build one desk of type A and 2 hours to build one desk of type B. It takes the second worker 4 hours to spray one desk of type A and 2 hours to spray one desk of type B. The first person works at least 5 hours a day, and the other works a maximum of 8 hours a day. If the factory earns a profit of 50 LE from each desk (of either type), determine how many desks of each type to produce each day to maximize the profit.

• A0 desks of type A, 2 desks of type B
• B2 desks of type A, 0 desks of type B
• C4 desks of type A, 0 desks of type B
• D0 desks of type A, 4 desks of type B

Q4:

A baby food factory produces two types of baby food with different nutritional values. One jar of the first type has 4 units of vitamin A and 2 units of vitamin B, while a jar of the second type has 2 units of vitamin A and 3 units of vitamin B. Every child requires at least 120 units of vitamin A and 100 units of vitamin B each month. The first type costs 6 LE per jar while the second costs 4 LE per jar. Using the graph below, determine how many of each type of jar should be bought to meet the child’s monthly needs at the lowest possible cost.

• Ajars of the first type , jars of the second type
• Bjars of the first type , jars of the second type
• Cjars of the first type , jars of the second type
• Djars of the first type , jars of the second type

Q5:

A baby food factory produces two types of baby food with different nutritional values. One jar of the first type has 2 units of vitamin A and 4 units of vitamin B, while a jar of the second type has 4 units of vitamin A and 2 units of vitamin B. Every child requires at least 100 units of vitamin A and 140 units of vitamin B each month. The first type costs 6 LE per jar while the second costs 4 LE per jar. Using the graph below, determine the objective function and then find the lowest possible cost required to supply a child with their required monthly nutrients.

• A , and the lowest possible cost is 280 LE.
• B , and the lowest possible cost is 100 LE.
• C , and the lowest possible cost is 1 800 LE.
• D , and the lowest possible cost is 220 LE.
• E , and the lowest possible cost is 420 LE.

Q6:

A candy store sells bags of marshmallows for 5 LE each and bags of cola candy for 6 LE each. A child wants to buy both types of candy and has restrictions on how many they can buy that are described by the figure shown, where represents the number of bags of marshmallows they buy and represents the number of bags of cola candy. What is the lowest price possible in this situation?

Q7:

Given that and , find the greatest possible value of .

Q8:

Given that and , find the smallest possible value of .

Q9:

Two packages of food supplies are available; the first gives 4 calories and has 6 units of vitamin C, and the second gives 3 calories and has 4 units of vitamin C. We need at least 37 calories and 22 units of vitamin C. The first costs 6 LE per package, and the second costs 8 LE per package. Using to represent the amount of packages of the first type and to represent the number of packages of the second type, state the objective function used to determine the minimum cost of buying packages to fulfil the nutrient needs.

• A
• B
• C
• D
• E

Q10:

In a workshop, two workers produce two types of iron desks: type A and type B. One worker builds the desks and the other sprays them. It takes the first worker 4 hours to build one desk of type A and 3 hours to build one desk of type B. It takes the second worker 3 hours to spray one desk of type A and 4 hours to spray one desk of type B. The first person works at least 5 hours a day, and the other works a maximum of 7 hours a day. If the workshop earns a profit of 60 LE from each desk (of either type), determine the objective function and inequalities required for calculating the number of desks of each type to be produced every day to maximize the profit .

• A , , , ,
• B , , , ,
• C , , , ,
• D , , , ,
• E , , , ,

Q11:

A baby food factory produces two types of baby food with different nutritional values. The first type, denoted by , costs 3 LE for one jar which contains 3 units of vitamin A and 2 of vitamin B. The second type, denoted by , costs 4 LE for one jar which contains 4 units of vitamin A and 3 of vitamin B. A child needs at least 120 units of vitamin A and 100 units of vitamin B to satisfy his nutrition needs. State the objective function and the inequality constraints needed to determine how many jars of each type to purchase to satisfy the nutrition requirements at the lowest possible cost.

• A , , , ,
• B , , , ,
• C , , , ,
• D , , , ,

Q12:

A small factory produces two types of metal furniture, and . They can produce at most 25 pieces of metal furniture in total. The profit from type is 60 LE and the profit from type is 40 LE. The factory sells at least 2 times more of type than type . State the objective function and inequalities that will help to find the maximum profit for the factory.

• A , , , ,
• B , , , ,
• C , , , ,
• D , , , ,

Q13:

A seafood restaurant sells two types of cooked fish; cod and eel. The restaurant sells NO LESS than 40 fish every day but it does not use more than 30 cod and no more than 45 eels. The price of one cod is 6 LE and that of an eel is 8 LE. Let represent the amount of cod purchased each day, and represent the amount of eel. Given that the manager wants to minimise the total price, , of fish, state the objective function and the inequalities that will help the restaurant manager decide how many of each fish to buy.

• A , , , , ,
• B , , , , ,
• C , , , , ,
• D , , , , ,
• E , , , , ,

Q14:

Given that and , find the greatest possible value of .

Q15:

A candy store sells bags of marshmallows for 7 LE each and bags of cola candy for 8 LE each. A child wants to buy both types of candy and has restrictions on how many they can buy that are described by the figure shown, where represents the number of bags of marshmallows they buy and represents the number of bags of cola candy. What is the lowest price possible in this situation?

Q16:

A candy store sells bags of marshmallows for 6 LE each and bags of cola candy for 4 LE each. A child wants to buy both types of candy and has restrictions on how many they can buy that are described by the figure shown, where represents the number of bags of marshmallows they buy and represents the number of bags of cola candy. What is the lowest price possible in this situation?

Q17:

A baby food factory produces two types of baby food with different nutritional values. One jar of the first type has 2 units of vitamin A and 4 units of vitamin B, while a jar of the second type has 4 units of vitamin A and 2 units of vitamin B. Every child requires at least 140 units of vitamin A and 100 units of vitamin B each month. The first type costs 6 LE per jar while the second costs 4 LE per jar. Using the graph below, determine the objective function and then find the lowest possible cost required to supply a child with their required monthly nutrients.

• A , and the lowest possible cost is 200 LE.
• B , and the lowest possible cost is 140 LE.
• C , and the lowest possible cost is 2 200 LE.
• D , and the lowest possible cost is 180 LE.
• E , and the lowest possible cost is 300 LE.

Q18:

A baby food factory produces two types of baby food with different nutritional values. One jar of the first type has 2 units of vitamin A and 3 units of vitamin B, while a jar of the second type has 4 units of vitamin A and 2 units of vitamin B. Every child requires at least 140 units of vitamin A and 120 units of vitamin B each month. The first type costs 6 LE per jar while the second costs 3 LE per jar. Using the graph below, determine how many of each type of jar should be bought to meet the child’s monthly needs at the lowest possible cost.

• Ajars of the first type , jars of the second type
• Bjars of the first type , jars of the second type
• Cjars of the first type , jars of the second type
• Djars of the first type , jars of the second type

Q19:

A factory produces two types of iron desks: Type A and Type B. One worker builds the desks and another sprays them. It takes the first worker 4 hours to build one desk of type A and 3 hours to build one desk of type B. It takes the second worker 2 hours to spray one desk of type A and 4 hours to spray one desk of type B. The first person works at least 5 hours a day, and the other works a maximum of 8 hours a day. If the factory earns a profit of 40 LE from each desk (of either type), determine how many desks of each type to produce each day to maximize the profit.

• A0 desks of type A, 4 desks of type B
• B0 desks of type A, 2 desks of type B
• C2 desks of type A, 0 desks of type B
• D4 desks of type A, 0 desks of type B

Q20:

A farmer can improve the quality of his produce if he uses at least 18 units of nitrogen-based compounds and at least 12 units of phosphate compounds. He can use two types of fertilizers: A and B. The cost and contents of each fertilizer are shown in the table.

The Fertilizer Number of Units of Nitrogen-Based Compounds per Kilogram Number of Units of Phosphate Compounds per Kilogram Cost for each Kilogram (LE)
A 6 3 200
B 2 2 190

Given that the graph represents the constraints in this situation, find the lowest cost the farmer can pay for fertilizer while providing sufficient amounts of both compounds.

Q21:

While on a trip you decide to buy cashews and pistachios. Given that you want to spend NOT more than 210 LE, the figure below illustrates the relation between the number of kilograms of cashews and pistachios you can buy. Determine the price of a kilogram of cashews and a kilogram of pistachios.

• Acashews = 3 LE, pistachios = 5 LE
• Bcashews = 168 LE, pistachios = 140 LE
• Ccashews = 70 LE, pistachios = 42 LE
• Dcashews = 42 LE, pistachios = 70 LE
• Ecashews = 5 LE, pistachios = 3 LE