New ! Business Maths and Statistics MCQ Practise Tests



Applications of Matrices and Determinants Important Questions

12th Standard

    Reg.No. :
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Business Maths

Time : 01:00:00 Hrs
Total Marks : 50
    5 x 1 = 5
  1. The rank of the matrix  \(\left( \begin{matrix} 1 & 1 & 1 \\ 1 & 2 & 3 \\ 1 & 4 & 9 \end{matrix} \right) \) is ________.

    (a)

    0

    (b)

    1

    (c)

    2

    (d)

    3

  2. If \(\rho (A)\) = r  then which of the following is correct?

    (a)

    all the minors of order r which does not vanish

    (b)

    A has at least one minor of order r which does not vanish

    (c)

    A has at least one (r+1) order minor which vanishes

    (d)

    all (r+1) and higher order minors should not vanish

  3. If  \(T=\begin{array}{l} A \\ B \end{array}\left(\begin{array}{ll} 0.7 & 0.3 \\ 0.6 & x \end{array}\right)\) is a transition probability matrix, then the value of x is ________.

    (a)

    0.2

    (b)

    0.3

    (c)

    0.4

    (d)

    0.7

  4. The rank of an n x n matrix each of whose elements is 2 is __________

    (a)

    1

    (b)

    2

    (c)

    n

    (d)

    n2

  5. If A, B are two n x n non-singular matrices, then ___________

    (a)

    AB is non-singular

    (b)

    AB is singular

    (c)

    (AB)-1 = A-1 B-1

    (d)

    (AB)-1 does not exit

  6. 5 x 2 = 10
  7. If A=\(\left( \begin{matrix} 1 & 1 & -1 \\ 2 & -3 & 4 \\ 3 & -2 & 3 \end{matrix} \right) \) and B=\(\left( \begin{matrix} 1 & -2 & 3 \\ -2 & 4 & -6 \\ 5 & 1 & -1 \end{matrix} \right) \), then find the rank of AB and the rank of BA.

  8. For what values of the parameter λ, will the following equations fail to have unique solution: 3x − y+λz = 1, 2x + y + z = 2, x + 2y − λz = −1 by rank method.

  9. Two types of soaps A and B are in the market. Their present market shares are 15% for A and 85% for B. Of those who bought A the previous year, 65% continue to buy it again while 35% switch over to B. Of those who bought B the previous year, 55% buy it again and 45% switch over to A. Find their market shares after one year and when is the equilibrium reached?

  10. Solve the equations x + 2y + z = 7, 2x − y + 2z = 4, x + y − 2z = −1 by using Cramer’s rule

  11. If A and B are non-singular matrices, prove that AB is non-singular.

  12. 5 x 3 = 15
  13. Find the rank of the matrix \(\left( \begin{matrix} 5 & 3 & 0 \\ 1 & 2 & -4 \\ -2 & -4 & 8 \end{matrix} \right) \)

  14. Find the rank of the matrix \(\left( \begin{matrix} 1 & 2 & -1 \\ 2 & 4 & 1 \\ 3 & 6 & 3 \end{matrix}\begin{matrix} 3 \\ -2 \\ -7 \end{matrix} \right) \)

  15. Show that the equations x + 2y = 3, y - z = 2, x + y + z = 1 are consistent and have infinite sets of solution.

  16. Show that the equations x- 3y + 4z = 3, 2x - 5y + 7z = 6, 3x - 8y + 11z = 1 are inconsistent

  17. Solve: 2x + 3y = 5, 6x + 5y = 11

  18. 2 x 5 = 10
  19. Solve the equations 2x + 3y = 7, 3x + 5y = 9 by Cramer’s rule.

  20. Using determinants, find the quadratic defined by f(x) = ax2 + bx + c if
    f(1) = 0,
    f(2) = - 2 and
    f(3) = -6.

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