Science (English Medium) कक्षा १२ - CBSE Question Bank Solutions for Mathematics

Maximize Z = 3x + 5y
Subject to

\[x + 2y \leq 20\]
\[x + y \leq 15\]
\[ y \leq 5\]
\[ x, y \geq 0\]

Minimize Z = 3x₁ + 5x₂
Subject to

\[x_1 + 3 x_2 \geq 3\]
\[ x_1 + x_2 \geq 2\]
\[ x_1 , x_2 \geq 0\]

Maximize Z = 2x + 3y
Subject to

\[x + y \geq 1\]
\[10x + y \geq 5\]
\[x + 10y \geq 1\]
\[ x, y \geq 0\]

Maximize Z = −x₁ + 2x₂
Subject to

\[- x_1 + 3 x_2 \leq 10\]
\[ x_1 + x_2 \leq 6\]
\[ x_1 - x_2 \leq 2\]
\[ x_1 , x_2 \geq 0\]

Maximize Z = x + y
Subject to

\[- 2x + y \leq 1\]
\[ x \leq 2\]
\[ x + y \leq 3\]
\[ x, y \geq 0\]

Maximize Z = 3x₁ + 4x₂, if possible,
Subject to the constraints 

\[x_1 - x_2 \leq - 1\]

\[ - x_1 + x_2 \leq 0\]

\[ x_1 , x_2 \geq 0\]

Maximize Z = 3x + 3y, if possible,
Subject to the constraints

\[x - y \leq 1\]
\[x + y \geq 3\]
\[ x, y \geq 0\]

Show the solution zone of the following inequalities on a graph paper:

Find the maximum and minimum value of 2x + y subject to the constraints:
x + 3y ≥ 6, x − 3y ≤ 3, 3x + 4y ≤ 24, − 3x + 2y ≤ 6, 5x + y ≥ 5, x, y ≥ 0.

Find the minimum value of 3x + 5y subject to the constraints
− 2x + y ≤ 4, x + y ≥ 3, x − 2y ≤ 2, x, y ≥ 0.

Solved the following linear programming problem graphically:
Maximize Z = 60x + 15y
Subject to constraints

\[x + y \leq 50\]
\[3x + y \leq 90\]
\[ x, y \geq 0\]

Find graphically, the maximum value of Z = 2x + 5y, subject to constraints given below:

2x + 4y ≤ 8

3x + y ≤ 6

x + y ≤ 4 

x ≥ 0, y ≥ 0   

Solve the following LPP graphically:
Maximize Z = 20 x + 10 y 
Subject to the following constraints 

\[x +\]2\[y \leq\]28 
3x+ \[y \leq\]24 
\[x \geq\] 2x.
\[y \geq\]  0

 Solve the following linear programming problem graphically:
Minimize  z = 6 x + 3 y
Subject to the constraints:

4 x + \[y \geq\] 80
x + 5 \[y \geq\] 115 

3 x + 2 \[y \leq\] 150
\[x \geq\] 0  , \[y \geq\] 0

A diet of two foods F₁ and F₂ contains nutrients thiamine, phosphorous and iron. The amount of each nutrient in each of the food (in milligrams per 25 gms) is given in the following table:

The minimum requirement of the nutrients in the diet are 1.00 mg of thiamine, 7.50 mg of phosphorous and 10.00 mg of iron. The cost of F₁ is 20 paise per 25 gms while the cost of F₂ is 15 paise per 25 gms. Find the minimum cost of diet.

To maintain one's health, a person must fulfil certain minimum daily requirements for the following three nutrients: calcium, protein and calories. The diet consists of only items I and II whose prices and nutrient contents are shown below:

Find the combination of food items so that the cost may be minimum.

A hospital dietician wishes to find the cheapest combination of two foods, A and B, that contains at least 0.5 milligram of thiamin and at least 600 calories. Each unit of Acontains 0.12 milligram of thiamin and 100 calories, while each unit of B contains 0.10 milligram of thiamin and 150 calories. If each food costs 10 paise per unit, how many units of each should be combined at a minimum cost?

A dietician mixes together two kinds of food in such a way that the mixture contains at least 6 units of vitamin A, 7 units of vitamin B, 11 units of vitamin C and 9 units of vitamin D. The vitamin contents of 1 kg of food X and 1 kg of food Y are given below:

One kg food X costs Rs 5, whereas one kg of food Y costs Rs 8. Find the least cost of the mixture which will produce the desired diet.

A diet is to contain at least 80 units of vitamin A and 100 units of minerals. Two foods F₁and F₂ are available. Food F₁ costs Rs 4 per unit and F₂ costs Rs 6 per unit one unit of food F₁ contains 3 units of vitamin A and 4 units of minerals. One unit of food F₂contains 6 units of vitamin A and 3 units of minerals. Formulate this as a linear programming problem and find graphically the minimum cost for diet that consists of mixture of these foods and also meets the mineral nutritional requirements