Q.A farmer has 10 hectares of land to allocate between wheat and mustard. Each hectare of wheat requires 6 labour-days and yields a profit of Rs 4,000; each hectare of mustard requires 4 labour-days and yields a profit of Rs 3,000. The farmer has at most 48 labour-days available. Formulate the linear programming problem to maximize the farmer's total profit.
🔒You're viewing a preview — the full solution, concept, methods & PYQ mapping are locked.
🔒 Start your 14-day free trial to unlock the full solution →Concept understanding — Linear Programming: Basic Terminology
A linear programming problem (LPP) optimizes a linear objective function Z=ax+by in decision variables x,y, subject to linear constraints (each a ≤ or ≥ inequality arising from a resource limit or a minimum requirement) and the non-negative restrictions x≥0, y≥0. Formulating an LPP from a word problem always follows the same four steps: name the decision variables, write the objective function using the given per-unit rates (profit, cost), translate each stated resource limit or requirement into one linear ineq …
Let x, y be the hectares under wheat and mustard; land and labour give the two constraints, and profit per hectare gives the objective. …
Let x= hectares under wheat and y= hectares under mustard.
Objective. Profit is Rs 4,000 per hectare of wheat and Rs 3,000 per hectare of mustard: Z=4000x+3000y (maximize).
Land available: x+y≤10. …
Let x, y be the hectares under wheat and mustard; total land gives one constraint, total labour-days gives the other (simplified by cancelling th …
Leaving the labour constraint as 6x+4y≤48 without simplifying (not wrong, but easy to mis-copy later); forgetting the land constraint …
- CBSE 2025Set ANNUAL5 marksQ.A farmer purchased some sheep and goats at Rs. 1,500 per sheep and Rs. 2,000 per goat, and makes a profit of Rs. 150 per sheep and Rs. 200 per goat after selling them. The farmer has only Rs. 60,000 and cannot accommodate more than 100 animals. He wishes to purchase both kinds of animals and to have maximum profit. Formulate the problem as a linear programming problem.
›Reveal solutionSolution
Identify the decision variables, the profit function to maximize, and translate each stated restriction into an inequality.
Decision variables: let x = number of sheep purchased, y = number of goats purchased.
Objective function: the farmer earns profit Rs.150 per sheep and Rs.200 per goat, so total profit:
Z=150x+200y(maximize)
Budget constraint: sheep cost Rs. 1,500 each and goats Rs. 2,000 each; total spend can't exceed Rs. 60,000:
1500x+2000y≤60000⇒3x+4y≤120(dividing by 500)
Capacity constraint: he cannot accommodate more than 100 animals:
x+y≤100
…
- CBSE 2024Set ANNUAL5 marksQ.A diet for a sick person must contain at least 4000 units of vitamins, 50 units of minerals and 1400 calories. Two foods A and B are available at a cost of Rs. 4 and Rs. 3 per unit respectively. If one unit of A contains 200 units of vitamins, 1 unit of mineral and 40 calories, and one unit of food B contains 100 units of vitamins, 2 units of minerals and 40 calories, formulate an L.P.P. so as to minimize the cost.
›Reveal solutionSolution
Define decision variables for units of each food, write the cost as the objective, and translate each nutrient requirement into a linear inequality.
Let x = number of units of food A, and y = number of units of food B.
Objective (minimize cost): Food A costs Rs.,4/unit, food B costs Rs.,3/unit, so:
Minimize Z=4x+3y
Constraints (from nutrient requirements):
Vitamins: A gives 200 units/unit, B gives 100 units/unit, at least 4000 needed:
200x+100y≥4000 ⇒ 2x+y≥40
Minerals: A gives 1 unit/unit, B gives 2 units/unit, at least 50 needed:
x+2y≥50
Calories: A gives 40/unit, B gives 40/unit, at least 1400 needed: …
- CBSE 2023Set ANNUAL5 marksQ.A manufacturer produces two models A and B of a product. Each piece of model A requires 9 labour-hours for fabricating and 1 labour-hour for finishing. Each piece of model B requires 12 labour-hours for fabricating and 3 labour-hours for finishing. For fabricating and finishing the maximum labour-hours available are 180 and 30 respectively. The company makes a profit of Rs. 8,000 on each piece of model A and Rs. 12,000 on each piece of model B. Formulate an L.P.P. so as to maximize his profit.
›Reveal solutionSolution
Translate each real-world limit (labour-hours available for fabricating, and for finishing) into a linear inequality, and the profit goal into a linear objective — that is the entire LPP formulation.
Step 1 — define decision variables. Let x= number of units of model A produced, y= number of units of model B produced. Both must be non-negative: x≥0, y≥0.
Step 2 — fabricating-hours constraint. Model A needs 9 labour-hours, model B needs 12, and only 180 hours are available:
9x+12y≤180.
Step 3 — finishing-hours constraint. Model A needs 1 hour, model B needs 3, and only 30 hours are available: …
- CBSE 2022Set ANNUAL5 marksQ.A dietician wishes to mix two types of foods in such a way that the mixture contain at least 8 units of Vitamin A and 10 units of Vitamin C. Food-I contains 2 units/kg of Vitamin A and 1 unit/kg of Vitamin C, while Food-II contains 1 unit/kg of Vitamin A and 2 units/kg of Vitamin C. It costs Rs. 50 per kg to purchase Food-I and Rs. 70 per kg to purchase Food-II. Formulate the above as a LPP to minimise the cost of such a mixture.
›Reveal solutionSolution
Translate each sentence of the word problem into a linear inequality: decision variables = kg of each food; objective = total cost; constraints = the minimum vitamin requirements.
Step 1 — define decision variables.
Let x = kg of Food-I used, y = kg of Food-II used.
Step 2 — write the objective function (minimise total cost). Food-I costs Rs.,50/kg, Food-II costs Rs.,70/kg:
Z=50x+70y(to be minimised)
Step 3 — write the constraints.
Vitamin A requirement: Food-I supplies 2 units/kg, Food-II supplies 1 unit/kg, and the mixture must have at least 8 units:
2x+y≥8
…
- CBSE 2019Set ANNUAL5 marksQ.A manufacturer produces two models A and B of a product. Each piece of model A requires 9 labour hours for fabricating and 1 labour hour for finishing. Each piece of model B requires 12 labour hours for fabricating and 3 labour hours for finishing. For fabricating and finishing the maximum labour hours available are 180 and 30 respectively. The company makes a profit of Rs. 8,000 on each piece of model A and Rs. 12,000 on each piece of model B. Formulate an L.P.P. so as to maximize his profit.
›Reveal solutionSolution
Translate labour and profit data into decision variables, an objective function, and constraints.
Let x = number of units of model A produced, y = number of units of model B produced.
Objective (profit to maximize): Model A gives ₹8,000 profit/unit, model B gives ₹12,000 profit/unit:
Maximize Z=8000x+12000y
Constraints:
- Fabricating hours: model A needs 9 hrs/unit, model B needs 12 hrs/unit, available 180 hrs: 9x+12y≤180
- Finishing hours: model A needs 1 hr/unit, model B needs 3 hrs/unit, available 30 hrs: x+3y≤30 …
🎓Unlock everything free for 14 days
- ✓Full step-by-step solutions
- ✓Concept-first explanations
- ✓Methods, shortcuts & mistakes
- ✓PYQ mapping + timed mock tests
Full access for 14 days. No credit card required.