You are using an out dated version of Internet Explorer.  Some features may not work correctly. Upgrade to   Google Chrome     Dismiss

Select Board & Class

Login

Board Paper of Class 12-Commerce 2011 Maths Delhi(SET 3) - Solutions

General Instructions:
i. All questions are compulsory.
ii. The question paper consists of 29 questions divided into three sections A, B and C. Section A comprises of 10 questions of one mark each, Section B comprises of 12 questions of four marks each, and Section C comprises of 7 questions of six marks each.
iii. All questions in section A are to be answered in one word, one sentence or as per the exact requirements of the question.
iv. There is no overall choice. However, internal choice has been provided in 4 questions of four marks each and 2 questions of six marks each. You have to attempt only one of the alternatives in all such questions.
v. Use of calculators is not permitted.
  • Question 3

    State the reason for the relation R in the set {1, 2, 3} given by R = {(1, 2), (2, 1)} not to be transitive.

    VIEW SOLUTION
  • Question 4

    For a 2 × 2 matrix, A = [aij] whose elements are given by , write the value of a12.

    VIEW SOLUTION
  • Question 5

    For what value of x, the matrix is singular?

    VIEW SOLUTION
  • Question 8

    For what value of ‘a’ the vectors and are collinear?

    VIEW SOLUTION
  • Question 9

    Write the direction cosines of the vector

    VIEW SOLUTION
  • Question 10

    Write the intercept cut off by the plane 2x + y z = 5 on x-axis.

    VIEW SOLUTION
  • Question 11

    Using properties of determinants, prove the following:

    VIEW SOLUTION
  • Question 12

    Find the values of a and b such that the following function f (x) is a continuous function:

    VIEW SOLUTION
  • Question 13

    Solve the following differential equation:

    VIEW SOLUTION
  • Question 14

    If two vectors are such that then find the value of

    VIEW SOLUTION
  • Question 15

    Consider the binary operation * on the set {1, 2, 3, 4, 5} defined by a * b = min. {a, b}. Write the operation table of the operation *.

    VIEW SOLUTION
  • Question 16

    Prove the following:

    OR

    Find the value of

    VIEW SOLUTION
  • Question 18

    Sand is pouring from a pipe at the rate of 12 cm3/s. The falling sand forms a cone on the ground in such a way that the height of the cone is always one-sixth of the radius of the base. How fast is the height of the sand cone increasing when the height is 4 cm?

    OR

    Find the points on the curve x2 + y2 − 2x − 3 = 0 at which the tangents are parallel to x-axis.

    VIEW SOLUTION
  • Question 20

    Solve the following differential equation:

    VIEW SOLUTION
  • Question 21

    Find the angle between the following pair of lines:

    and check whether the lines are parallel or perpendicular.

    VIEW SOLUTION
  • Question 22

    Probabilities of solving a specific problem independently by A and B are and respectively. If both try to solve the problem independently, find the probability that (i) the problem is solved (ii) exactly one of them solves the problem.

    VIEW SOLUTION
  • Question 23

    A man is known to speak truth 3 out of 4 times. He throws a die and reports that it is a six.

    Find the probability that it is actually a six.

    VIEW SOLUTION
  • Question 24

    Show that of all the rectangles of given area, the square has the smallest perimeter.

    VIEW SOLUTION
  • Question 25

    Using matrix method, solve the following system of equations:

    OR

    Using elementary transformations, find the inverse of the matrix

    VIEW SOLUTION
  • Question 26

    Using integration find the area of the triangular region whose sides have equations y = 2x + 1, y = 3x + 1 and x = 4.

    VIEW SOLUTION
  • Question 28

    Find the equation of the plane which contains the line of intersection of the planes and which is perpendicular to the plane

    VIEW SOLUTION
  • Question 29

    A factory makes tennis rackets and cricket bats. A tennis racket takes 1.5 hours of machine time and 3 hours of craftsman’s time in its making while a cricket bat takes 3 hours of machine time and 1 hour of craftsman’s time. In a day, the factory has the availability of not more than 42 hours of machine time and 24 hours of craftsman’s time.

    If the profit on a racket and on a bat is Rs 20 and Rs 10 respectively, find the number of tennis rackets and cricket bats that the factory must manufacture to earn the maximum profit. Make it as an L.P.P. and solve graphically.

    VIEW SOLUTION
More Board Paper Solutions for Class 12 Commerce Math
What are you looking for?

Syllabus