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CBSE Class 12 Maths 2026 Question Paper 65/1/3 with Solutions

All 46 questions from the CBSE Class 12 Mathematics board paper, Set 65/1/3 (2026), with answers and step-by-step solutions. Total 80 marks. Tap “Show answer & solution” under any question.

Set 65/1/1Set 65/1/2Set 65/1/3Set 65/2/1Set 65/2/2Set 65/2/3Set 65/3/1Set 65/3/2Set 65/3/3Set 65/4/1Set 65/4/2Set 65/4/3Set 65/5/1Set 65/5/2Set 65/5/3
Q11 markMCQVector Algebra

If and , then the value of

  1. (A)
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (C)
  1. .
  2. So .
  3. .
Also asked in: 2026 65/1/1, 2026 65/1/2

The length of perpendicular drawn from the point (3, 4, 2) on the line is

  1. (A)2
  2. (B)9
  3. (C)5
  4. (D)
Show answer & solution
Answer: (C) 5
  1. The line has direction ratios 0, 0, 1 and passes through the origin, so it is the -axis.
  2. Foot of the perpendicular from (3, 4, 2) is (0, 0, 2).
  3. Length .

The feasible region of a linear programming problem with objective function is shown below :
The maximum value of Z – minimum value of Z is

Diagram for CBSE 2026 Class 12 Maths question 3
  1. (A)8
  2. (B)29
  3. (C)35
  4. (D)43
Show answer & solution
Answer: (D) 43
  1. Corner points: O(0, 0), (0, 2), (3, 4), (7, 0).
  2. Z at these: 0, 14, 15 + 28 = 43, 35.
  3. Maximum , minimum .
  4. Maximum minimum .
Also asked in: 2026 65/1/1, 2026 65/1/2

The degree of an objective function of a linear programming problem is

  1. (A)0
  2. (B)1
  3. (C)2
  4. (D)Any natural number
Show answer & solution
Answer: (B) 1
  1. The objective function of an LPP is linear, e.g. .
  2. So its degree is 1.
Also asked in: 2026 65/1/1, 2026 65/1/2

If , then

  1. (A)
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (C)
  1. The range of is .
  2. Adding : , i.e. .
Q61 markMCQMatrices

If is a scalar matrix then which of the following must be true ?

  1. (A)A must be a symmetric matrix.
  2. (B)A must be a skew-symmetric matrix.
  3. (C)A must be an identity matrix.
  4. (D)A must be a null matrix.
Show answer & solution
Answer: (A) A must be a symmetric matrix.
  1. A scalar matrix is a diagonal matrix with all diagonal entries equal to some k, i.e. .
  2. Then , so A is always symmetric.
  3. It is an identity matrix only if , a null matrix only if , and skew-symmetric only if .
Q71 markMCQMatrices

Which of the following properties is/are true for two matrices of suitable orders ?
(i)
(ii)
(iii)
(iv) (k is a scalar)

  1. (A)(i) only
  2. (B)(i), (ii) and (iii)
  3. (C)(i) and (ii)
  4. (D)(i) and (iv)
Show answer & solution
Answer: (D) (i) and (iv)
  1. (i) is true.
  2. (ii) , not , so (ii) is false.
  3. (iii) , not , so (iii) is false.
  4. (iv) , so (iv) is true.
  5. Hence (i) and (iv).
Also asked in: 2026 65/1/1, 2026 65/1/2
Q81 markMCQDeterminants

If and , then

  1. (A)
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (B)
  1. (diagonal determinant).
  2. Expanding along : .
  3. So .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q91 markMCQDeterminants

One of the values of for which is

  1. (A)0
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (B)
  1. .
  2. .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q101 markMCQMatrices

If A and B are symmetric matrics of same order, then (AB – BA) is a

  1. (A)Zero matrix
  2. (B)Identity matrix
  3. (C)Symmetric matrix
  4. (D)Skew symmetric matrix
Show answer & solution
Answer: (D) Skew symmetric matrix
  1. Given , .
  2. .
  3. So is skew symmetric.

The least value of in [0, 3] is

  1. (A)
  2. (B)
  3. (C)1
  4. (D)
Show answer & solution
Answer: (A)
  1. , so f is decreasing on [0, 3].
  2. Least value .
Q121 markMCQIntegrals

If , then the value of A is

  1. (A)3a
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (D)
  1. Put , so .
  2. .
  3. So .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q131 markMCQIntegrals

The value of is

  1. (A)0
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (A) 0
  1. Let . Then , so is odd.
  2. For an odd function, .
  3. So the value is 0.
Also asked in: 2026 65/1/1, 2026 65/1/2

The area bounded by the curve , -axis and the ordinates and is given by

  1. (A)0
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (C)
  1. For , ; for , . The curve is symmetric about the origin.
  2. Area sq unit.
Also asked in: 2026 65/1/1, 2026 65/1/2

The integrating factor of differential equation where P, Q, R are functions of y is

  1. (A)
  2. (B)
  3. (C)
  4. (D)
Show answer & solution
Answer: (C)
  1. Divide by R: , a linear equation in .
  2. Integrating factor .
Also asked in: 2026 65/1/1, 2026 65/1/2

The order and degree of the differential equation :
respectively are where

  1. (A)1, 3
  2. (B)2, 1
  3. (C)3, 1
  4. (D)3, 2
Show answer & solution
Answer: (B) 2, 1
  1. , so the equation is .
  2. Highest derivative is , so order .
  3. appears with power 1, so degree .
Q171 markMCQVector Algebra

The value of p for which vectors and are perpendicular to each other is

  1. (A)0
  2. (B)1
  3. (C)
  4. (D)
Show answer & solution
Answer: (C)
  1. Perpendicular vectors have zero dot product.
  2. .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q181 markMCQVector Algebra

The value of m for which the points with position vectors , and are collinear, is

  1. (A)8
  2. (B)
  3. (C)2
  4. (D)
Show answer & solution
Answer: (A) 8
  1. Let the points be A, B, C. , .
  2. For collinearity, : .
  3. So , i.e. .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q191 markAssertion–ReasonProbability

Assertion (A): In an experiment of throwing an unbiased die, the probability of getting a prime number given that number appearing on the die being odd is .
Reason (R): For any two events A and B,

  1. (A)Both Assertion (A) and Reason (R) are true and the Reason (R) is the correct explanation of the Assertion (A).
  2. (B)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  3. (C)Assertion (A) is true and Reason (R) is false.
  4. (D)Assertion (A) is false and Reason (R) is true.
Show answer & solution
Answer: (C) Assertion (A) is true and Reason (R) is false.
  1. Odd outcomes: {1, 3, 5}. Prime among them: {3, 5}.
  2. , so A is true.
  3. The correct formula is , not with , so R is false.
Also asked in: 2026 65/1/1, 2026 65/1/2
Q201 markAssertion–ReasonThree Dimensional Geometry

Assertion (A): Lines given by and are perpendicular to each other when .
Reason (R): Two lines and are perpendicular to each other if .

  1. (A)Both Assertion (A) and Reason (R) are true and the Reason (R) is the correct explanation of the Assertion (A).
  2. (B)Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
  3. (C)Assertion (A) is true and Reason (R) is false.
  4. (D)Assertion (A) is false and Reason (R) is true.
Show answer & solution
Answer: (D) Assertion (A) is false and Reason (R) is true.
  1. First line: , direction ratios .
  2. Second line: direction ratios .
  3. Perpendicular , i.e. . So A is false.
  4. R is the standard condition for perpendicular lines, so R is true.
Also asked in: 2026 65/1/1, 2026 65/1/2
Q212 marksVery Short AnswerInverse Trigonometric Functions

Simplify : .

Show answer & solution
Answer:
  1. Divide numerator and denominator by : .
  2. For , , which lies in .
  3. So .
Also asked in: 2026 65/1/1, 2026 65/1/2
OR
Q21 (OR) (OR)2 marksVery Short AnswerInverse Trigonometric Functions

Evaluate :

Show answer & solution
Answer:
  1. and .
  2. .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q222 marksVery Short AnswerContinuity and Differentiability

Check whether function f(x) defined as
is continuous at or not ?

Show answer & solution
Answer: is continuous at .
  1. For , , so .
  2. LHL .
  3. RHL .
  4. .
  5. LHL = RHL = , so is continuous at .
Also asked in: 2026 65/1/1, 2026 65/1/2
OR
Q22 (OR) (OR)2 marksVery Short AnswerContinuity and Differentiability

If , then find at .

Show answer & solution
Answer:
  1. Differentiate w.r.t. : .
  2. .
  3. At : numerator , denominator .
  4. .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q232 marksVery Short AnswerInverse Trigonometric Functions

Simplify : .

Show answer & solution
Answer:
  1. , and for , so the square root is .
  2. .
  3. Since , this equals .
OR
Q23 (OR) (OR)2 marksVery Short AnswerInverse Trigonometric Functions

Evaluate : .

Show answer & solution
Answer:
  1. and (principal values).
  2. .
Q242 marksVery Short AnswerVector Algebra

Using vectors, find the area of with vertices A(1, 2, 3), B(2, -1, 4) and C(4, 5, -1).

Show answer & solution
Answer: sq units
  1. , .
  2. .
  3. .
  4. Area sq units.
Q252 marksVery Short AnswerVector Algebra

Vectors and represent the two adjacent sides of a parallelogram. Find the vectors representing its diagonals and hence find their lengths.

Show answer & solution
Answer: Diagonals (length 6) and (length )
  1. Diagonals are and .
  2. , length .
  3. , length .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q263 marksShort AnswerIntegrals

Evaluate :

Show answer & solution
Answer:
  1. By parts: .
  2. First term .
  3. .
  4. Value .
Q273 marksShort AnswerProbability

Out of two bags, bag I contains 3 red and 4 white balls and bag II contains 8 red and 6 white balls. A die is thrown. If it shows a number less than 3 then a ball is drawn at random from bag I, otherwise a ball is drawn at random from bag II. Find the probability that the ball drawn from one of the bags is a red ball.

Show answer & solution
Answer:
  1. Let : die shows 1 or 2 (bag I), : die shows 3, 4, 5 or 6 (bag II). , .
  2. Let R: red ball drawn. , .
  3. .
Also asked in: 2026 65/1/1, 2026 65/1/2
OR
Q27 (OR) (OR)3 marksShort AnswerProbability

The probability of simultaneous occurrence of atleast one of the two events X and Y is a. If the probability that exactly one of the events X, Y occurs is b, prove that .

Show answer & solution
Answer: Proved.
  1. Given .
  2. Exactly one occurs: .
  3. Subtracting: , so .
  4. . Hence proved.
Also asked in: 2026 65/1/1, 2026 65/1/2
Q283 marksShort AnswerIntegrals

Find

Show answer & solution
Answer:
  1. .
  2. (put ).
  3. .
  4. So the integral .
Also asked in: 2026 65/1/1, 2026 65/1/2
OR
Q28 (OR) (OR)3 marksShort AnswerIntegrals

Find :

Show answer & solution
Answer:
  1. Put for the partial fractions: .
  2. : ; : .
  3. So .
  4. Integral .
Also asked in: 2026 65/1/1, 2026 65/1/2
Q293 marksShort AnswerIntegrals

If and , then show that .

Show answer & solution
Answer: Proved.
  1. .
  2. is even, so .
  3. . Hence proved.
Also asked in: 2026 65/1/1, 2026 65/1/2
Q303 marksShort AnswerDifferential Equations

Find the general solution of the differential equation

Show answer & solution
Answer:
  1. , a homogeneous equation.
  2. Put : .
  3. .
  4. So , i.e. .
  5. General solution: .
OR
Q30 (OR) (OR)3 marksShort AnswerDifferential Equations

Find the particular solution of the differential equation
, given that y(1) = 0.

Show answer & solution
Answer:
  1. Separate: .
  2. Put on the right: .
  3. So .
  4. : .
  5. Particular solution: .
Q313 marksShort AnswerLinear Programming

Solve the following linear programming problem graphically :
Minimize
Subject to constraints


Show answer & solution
Answer: Minimum Z = at (0, 2)
  1. Lines: and (through (0, 2) and (-3, 0)).
  2. They meet where .
  3. The feasible region is bounded with corner points O(0, 0), A(7, 0), B(3, 4), C(0, 2).
  4. Z at these: 0, 91, 39 - 60 = -21, -30.
  5. Minimum Z = at (0, 2).
Also asked in: 2026 65/1/1, 2026 65/1/2
Q325 marksLong AnswerThree Dimensional Geometry

Show that line AB passing through points A(0, 4, 1), B(2, 3, -1) and the line CD passing through points C(4, 5, 0), D(2, 6, 2) are parallel. Also, find distance between them.

Show answer & solution
Answer: The lines are parallel; distance units.
  1. and , so AB CD.
  2. Take , (A), (C).
  3. .
  4. , magnitude 9.
  5. . Distance units (non-zero, so the lines are distinct).
Q335 marksLong AnswerRelations and Functions

A relation R is defined on Z, the set of integers, as
is divisible by a prime number 'p',
check whether R is an equivalence relation or not.

Show answer & solution
Answer: R is an equivalence relation.
  1. Take p as a fixed prime.
  2. Reflexive: is divisible by p, so for all .
  3. Symmetric: if then p divides , so .
  4. Transitive: if then and for integers k, m.
  5. Adding, , so p divides and .
  6. R is reflexive, symmetric and transitive, so R is an equivalence relation.
Also asked in: 2026 65/1/1, 2026 65/1/2
OR
Q33 (OR) (OR)5 marksLong AnswerRelations and Functions

A function is defined as . Show that f is one-one and onto.

Show answer & solution
Answer: Proved.
  1. One-one: let . Then .
  2. . So f is one-one.
  3. Onto: let and solve .
  4. , defined since .
  5. Also : otherwise , impossible.
  6. Then , so every y has a pre-image and f is onto.
Also asked in: 2026 65/1/1, 2026 65/1/2
Q345 marksLong AnswerDeterminants

If , find and use it to solve the following system of equations :

Show answer & solution
Answer: ;
  1. .
  2. Cofactors: .
  3. , so .
  4. The system is with , , since the coefficient matrix .
  5. .
  6. So .
Also asked in: 2026 65/1/1, 2026 65/1/2
OR
Q34 (OR) (OR)5 marksLong AnswerDeterminants

If is a singular matrix, then find all values of where .

Show answer & solution
Answer:
  1. Singular means the determinant is 0. Expand along .
  2. Cofactors: , , .
  3. .
  4. With : .
  5. or ( is impossible).
  6. In : or .
Also asked in: 2026 65/1/1, 2026 65/1/2

If and , then find and .

Show answer & solution
Answer: ;
  1. .
  2. .
  3. .
  4. .
Q364 marksCase StudyApplication of Integrals

Roundabouts are often made on busy roads to ease the traffic and avoid red lights.
One such round-about is made such that equation representing its boundary is given by .
There is a circular pond with a fountain in the middle of the roundabout whose equation is given by .
Based on the given information, answer the following questions :
(i) Represent the given equations and with the help of a diagram. (1)
(ii) Express y as a function of , (y = f(x)), for both an . (1)
(iii) Using integration find the area of region covered by the roundabout. (2)
OR (iii) Using integration, find the area of region covered by circular pond. (2)

Show answer & solution
Answer: (i) Two concentric circles with centre O(0, 0) and radii 8 and 2 (ii) : ; : (iii) sq units; OR sq units
  1. (i) is a circle with centre (0, 0) and radius 8; is a circle with centre (0, 0) and radius 2, inside .
  2. (ii) : , ; : , .
  3. (iii) By symmetry, area sq units.
  4. OR (iii) Area sq units.
Also asked in: 2026 65/1/1, 2026 65/1/2
Q374 marksCase StudyApplication of Derivatives

An online delivery company in a city has 5000 subscribers and collects annual subscription fees of ₹ 300 per subscriber for unlimited free deliveries.
The company wishes to increase the annual subscription fee. It is predicted that, for every increase of ₹ 1, ten subscribers will discontinue. Assume that the company increased the annual fee by ₹ .
Based on the given information, answer the following questions :
(i) How many subscribers will discontinue after an increase of ₹ in annual fee ? (1)
(ii) If R(x) denotes the total revenue collected after the increase of ₹ in subscription fee, express R(x) as a function of . (1)
(iii) Find the value of for which R(x) is maximum. (2)
OR (iii) Find the sub-intervals of (0, 5000) in which R(x) is increasing and decreasing. (2)

Diagram for CBSE 2026 Class 12 Maths question 37
Show answer & solution
Answer: (i) (ii) (iii) ; OR increasing on (0, 100), decreasing on (100, 5000)
  1. (i) 10 subscribers leave per ₹ 1 increase, so subscribers discontinue.
  2. (ii) Fee , subscribers , so .
  3. (iii) . , so R is maximum at .
  4. OR (iii) : on (0, 100) and on (100, 5000).
  5. So R is increasing on (0, 100) and decreasing on (100, 5000).
Also asked in: 2026 65/1/1, 2026 65/1/2
Q384 marksCase StudyProbability

In an online jackpot, there is one first prize of ₹ 3,00,000, two second prizes of ₹ 2,00,000 each and three third prizes of ₹ 50,000 each.
A total of 1,00,000 jackpot tickets each costing ₹ 100 were sold there by raising a fund of ₹ 1,00,00,000.
Rohan bought one ticket.
Based on given information, answer the following questions :
(i) What are the possible amounts, the person can win ? (1)
(ii) What is the probability that the person wins atleast ₹ 2,00,000 ? (2)
OR (ii) What is the probability that the person does not win any amount ? (2)
(iii) In another jackpot, Rohan also bought a ticket having a prize money of ₹ 5,00,000. The chances of winning the jackpot are 1 in 1,00,000. Find the probability that on exactly one of tickets he wins the jackpot. (1)

Show answer & solution
Answer: (i) ₹ 3,00,000, ₹ 2,00,000, ₹ 50,000 (or ₹ 0) (ii) ; OR (iii)
  1. (i) He can win ₹ 3,00,000, ₹ 2,00,000 or ₹ 50,000, or nothing (₹ 0).
  2. (ii) Tickets winning at least ₹ 2,00,000: 1 + 2 = 3. Probability .
  3. OR (ii) Winning tickets: 1 + 2 + 3 = 6. P(no prize) .
  4. (iii) Take P(jackpot on the first ticket) = P(first prize) and P(jackpot on the second ticket) , independent.
  5. P(exactly one) .
Also asked in: 2026 65/1/1, 2026 65/1/2
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