Showing posts with label Linear Algebra and Optimization. Show all posts
Showing posts with label Linear Algebra and Optimization. Show all posts

August 26, 2019

Linear Algebra and Optimization- MCQS

Note: We have tried to upload as much as we can, all the question and answers might be shuffled - Please find the answer below each question, some answers might be wrong please review on the last date(some answers might be changed) if you find any of the answer is wrong please comment down below. 


Question 1:
When using a graphical solution procedure, the region bounded by the set of constraints is called the
Select one:
A.feasible region
B.infeasible region
C.maximum profit region
D.none of the above
Correct Answer is : A

Question 2:
An LP problem has a bounded feasible region. If this problem has an equality constraint, then
Select one:
A.this must be a minimization problem
B.the feasible region must consist of a line segment
C.the problem must be degenerate
D.the problem must have more than one optimal solution
Correct Answer is : B

Question 3:
If two constraints do not intersect in the positive quadrant of the graph, then
Select one:
A.The Problem is infeasible
B.The solution is unbounded
C.One of the constraints is redundant.
D.The solution is optimal
Correct Answer is : A

Question 4:
For a maximization problem, the coefficient for an artificial variable in the objective function while using two phase simplex method is
Select one:
A.+1
B.-1
C.+M
D.–M
Correct Answer is : B

Question 5:
When alternate optimal solutions exist in an LP problem, then
Select one:
A.the objective function will be parallel to one of the constraints
B.one of the constraints will be redundant
C.two constraints will be parallel
D.the problem will also be unbounded
Correct Answer is : A

Question 6:
A optimum solution to an LP problem
Select one:
A.Must satisfy all of the problem’s constraints simultaneously
B.Need not satisfy all of the constraints, only some of them
C.Must be corner point of the feasible region
D.Must optimize the value of the objective function
Correct Answer is :  D

Question 7:
If the constraint has ‘≥’ sign, then we introduce
Select one:
A.Surplus variable
B.Slack variable
C.artificial variable
D.Slack and surplus variables
Correct Answer is : A

Question 8:
If the feasible region gets larger due to a change in one of the constraints, the optimal value of the objective function
Select one:
A.must increase or remain the same for a maximization problem
B.must decrease or remain the same for a maximization problem
C.must increase or remain the same for a minimization problem
D.cannot change
Correct Answer is : A

Question 9:
If there is no feasible region in a LPP, then we say that the problem has
Select one:
A.Infinite solution
B.No solution
C.Unbounded solution
D.None of these
Correct Answer is : B

Question 10:
A graphical method should only be used to solve an LP problem when
Select one:
A.there are only two constraints
B.there are more than two constraints
C.there are only two variables
D.there are more than two variables
Correct Answer is : C

Question 11:
Which of the following is true with respect to the optimal solution of an LPP
Select one:
A.Every LPP has an optimal solution
B.Optimal solution of an LPP always occurs at an extreme point
C.At optimal solution all resources are used completely
D.If an optimal solution exists, there will always be at least one at a corner
Correct Answer is : D

Question 12:
If a linear program is unbounded, the problem probably has not been formulated correctly. Which of the following would most likely cause this?
Select one:
A.a constraint was inadvertently omitted
B.an unnecessary constraint was added to the problem
C.the objective function coefficients are too large
D.the objective function coefficients are too small
Correct Answer is : A

Question 13:
A linear program has been solved and sensitivity analysis has been performed. The ranges for the objective function coefficients have been found. For the profit on the upper bound is 80, the lower bound is 60, and the current value is 75. Which of the following must be true if the profit on this  variable is lowered to 70 and the optimal? Solution is found?
Select one:
A.a new corner point will become optimal
B.the maximum possible total profit may increase
C.the values for all the decision variables will remain the same
D.all of the above are possible
Correct Answer is : C

Question 14:
Maximize z = 3x + 4y subject to the constraints: 4x + 2y  80 , 2x + 5y  180 , x , y ≥ 0
Select one:
A.0 at (0, 0)
B.180 at (20, 30)
C.115 at (35, 2.5)
D.147.5 at (2.5, 35)
Correct Answer is : D

Question 15:
Which of the following would cause a change in the feasible region?
Select one:
A.increasing an objective function coefficient in a maximization problem
B.adding a redundant constraint
C.changing the right-hand side of a no redundant constraint
D.increasing an objective function coefficient in a minimization problem
Correct Answer is : C

Question 16:
A constraint that does not affect the feasible solution is a
Select one:
A.non-negative constraint
B.a redundant constraint
C.standard constraint
D.slack constraint
Correct Answer is : B

Question 17:
Which of the following is a valid objective function for  LPP?
Select one:
A.maximize 6xyz
B.maximize  3x +4y – z
C.minimize 5x2+7y3
D.none of these
Correct Answer is : B

Question 18:
In the optimal solution to a linear program, there are 20 units of slack for a constraint. From this we know that
Select one:
A.the dual price for this constraint is 20
B.the dual price for this constraint is 0
C.this constraint must be redundant
D.the problem must be a maximization problem
Correct Answer is : B

Question 19:
Lower and upper bounds in case of an unbounded variable is
Select one:
A.0 and ∞
B.– ∞ and 
C.0 and - ∞
D.none of these
Correct Answer is : A

Question 20:
Mathematical model of LP problem is important because
Select one:
A.It helps in converting the verbal description and numerical data into mathematical expression
B.Decision – makers prefer to work with formal models
C.It captures the relevant relationship among decision factors
D.It enables the use of algebraic techniques
Correct Answer is : A

Question 21:
From a set of equations x + 4y – z = 3 and 5x + 2y + 3z = 4 the basic feasible solution involving x, y is
Select one:
A.(5/9, 11/18, 0)
B.(5/9, 0, 0)
C.(0, 11/18, 0)
D.none of these
Correct Answer is : A

Question 22:
If a negative value appears in the solution values column of the simplex table, then
Select one:
A.the solution is optimal
B.the solution is infeasible
C.the solution is unbounded
D.all of the above
Correct Answer is : C

Question 23:
In solving a linear program, no feasible solution exists. To resolve this problem we might
Select one:
A.add another variable
B.add another constraint
C.remove or relax a constraint
D.try a different computer program
Correct Answer is : C

Question 24:
In LP, variables do not have to be integer valued and may take on any fractional value This assumption is called
Select one:
A.proportionality
B.divisibility
C.additivity
D.certainty
Correct Answer is : B

Question 25:
The role of artificial variable in the simplex method is
Select one:
A.To find optimal dual prices in the final simplex table
B.to start phases of simple method
C.to aid in finding an initial solution
D.convert inequality constraints into equality
Correct Answer is : C

Question 26:
Which of the following subroutines does a computer implementation in LPP by the simplex method use?
Select one:
A.Finding a root of a polynomial
B.Finding the determinant of a matrix
C.Finding the Eigen value of a matrix
D.Solving a system of linear equations
Correct Answer is : D

Question 27:
A feasible solution to an LP problem
Select one:
A.must satisfy all of the problem’s constraints simultaneously.
B.need not satisfy all of the constraints, only some of them
C.must be a corner point of the feasible region
D.must give the maximum possible profit
Correct Answer is : A

Question 28:
Let S1- The slack and surplus variables can be unrestricted in sign
S2 – A basic feasible solution cannot have zero value for any of the variables
Select one:
A.S1 – True, S2 – True
B.S1 – False, S2 - True
C.S1 – True, S2 – False
D.S1 – False, S2 – False
Correct Answer is : D

Question 29:
If dual has an unbounded solution, primal has
Select one:
A.Unbounded solution
B.Feasible solution
C.Infeasible solution
D.Optimum solution
Correct Answer is : C

Question 30:
If a non redundant constraint is removed from an LP problem, then
Select one:
A.the feasible region will get larger
B.the feasible region will get smaller
C.the problem would become nonlinear
D.the problem would become infeasible
Correct Answer is : A


June 12, 2019

Linear Algebra and Optimization- MCQS

Note : We have tried upload as much as we can, all the question and answers might be shuffled - Answers are marked in green. Thanks for Murthy,Abirami who helped us on this quiz.

Questions:

1. In R^3   the four vectors (1,2,5)  (5,9,3) (329,431,731) and (21, -13,58) are
Select one:
A. Linearly dependent
B. Every linear combination is zero
C. Linearly Independent
D. Forms a basis for R^3

The correct answer: Linearly dependent

 2. 

Select one:
A. 45
B. 0
C. 10
D. 3

The correct answer: 0

3. The elements along principal diagonal of a Hermitian matrix are all

Select one:
A. either zero or purely imaginary
B. real
C. 0
D. imaginary

The correct answer: real

4. For the linearly dependent vectors  X=[3,-9,12] and Y=[-4,12,-16]:

Select one:
A. X-2Y=0
B. 4X+3Y=0
C. 4X-3Y=0
D. 3X+4Y=0

The correct answer: 4X+3Y=0

5. If A and B are two orthogonal matrices, each of order n then AB and BA are

Select one:
A. Orthogonal
B. asymmetric
C. symmetric
D. Hermitian

The correct answer: asymmetric

6. A set of single non-zero vector is

Select one:
A. Basis
B. None
C. Linearly dependent
D. Linearly Independent

The correct answer: Linearly Independent

7.Which one of the following is false :

Select one:
A. Matrices is an arrangement while determinant is a value of square matrices.
B. If Rank of A= Rank of B
C. Row equivalent matrices have the same rank.
D. A linearly independent set in v consisting on a maximum possible no of vectors in V is called a basis for V

The correct answer: If Rank of A= Rank of B

8. The Gauss-Elimination method, the augmented matrix reduces to…..................matrix

Select one:
a. Upper triangular
b. Diagonal
c. unit
d. None of these

The correct answer: Upper triangular



9. The Characteristics roots of an orthogonal matrix are of ------ modulus



Select one:
A. Unit
B. Two
C. Three
D. Zero



The correct answer: Unit



10.Which of the following is not a elementary transformation?

Select one:
a. Adding two rows
b. Squaring all the elements of the matrix
c. Adding two columns
d. Multiplying a row by a non-zero number

The correct answer: Squaring all the elements of the matrix



11. 

Select one:
A.




B.


C.



D.

The correct answer: C

12. If  rank = number of unknowns  and x = y = z = 0 the equation have only -------- solution

Select one:
A. Non trivial
B. Infinite
C. Unique
D. Trivial

The correct answer: Trivial


13. 

Select one:
A. 3
B. 9
C. 1
D. -3

The correct answer: 3

14.If r is the rank of the matrix [A] of order m x n then r is

Select one:
A. r is less than or equal to minimum of (m, n)
B. r is greater than or equal to 'm'
C. r is greater than 'n'
D. r is less than or equal to 'n'

The correct answer: r is less than or equal to 'n'

15. The standard basis of an inner product space R x R x R (R) forms  an

Select one:
A. Orthonormal set
B. Orthogonal set and Orthonormal set
C. Orthogonal set
D. Neither Orthogonal set nor Orthonormal set

The correct answer: Orthogonal set and Orthonormal set

16. Let A be a matrix having rank ‘r ' & B be the equivalent matrix obtained from A. Then rank of   matrix B is…

Select one:
A. r + 2
B. r -1
C. r
D. r + 1

The correct answer: r

17. State : which one is false :
Select one:
A. If A and B are Hermitian: then AB-BA is skew Hermitian

B.



C. If A  is a  skew Hermitian : then iA  is Hermitian

D.


The correct answer: D

18. 

Select one:
A. 6,6    
B. 6,-12    
C. 12,6   
D. -6,12.

The correct answer: 6,-12

19. The linear transformation Y = AX is regular if

Select one:
A. I A I#0
B. I A I=1
C. I A I=-1
D. I A I=0

The correct answer: I A I#0

20. A square matrix A of order 3 has 3 linearly independent Eigen vectors then a matrix P can be found such that   P-1AP is a

Select one:
A. Diagonal Matrix
B. Symmetric matrix
C. Singular matrix
D. Unit matrix

The correct answerDiagonal Matrix