Practice Questions

Q68.Let A and B be two square matrices of order 3 such that |A| = 3 and |B| = 2. Then ATA(adj(2 A))−1(adj(4 B))(adj(AB))−1AAT is equal to : (1) 108 (2) 32 (3) 81 (4) 64 Q69. 11x + y + λz = −5 If the system of equations 2x + 3y + 5z = 3 has infinitely many solutions, then λ4 −μ is equal to : 8x −19y −39z = μ (1) 51 (2) 45 (3) 47 (4) 49

Q68.Let R be a relation on Z × Z defined by (a, b)R(c, d) if and only if ad −bc is divisible by 5 . Then R is (1) Reflexive and symmetric but not transitive (2) Reflexive but neither symmetric not transitive (3) Reflexive, symmetric and transitive (4) Reflexive and transitive but not symmetric Q69. ⎡ 1 0 0 ⎤ 3 Let A = 0 α β and 2A = 221 where α, β ∈Z , Then a value of α is ⎣ 0 β α⎦ (1) 3 (2) 5 (3) 17 (4) 9 is equal to

Q68.If lim 3 + 𝛼sin𝑥+ 𝛽cos𝑥+ log𝑒( 1 - 𝑥) = 1 then 2𝛼- 𝛽 is equal to : 𝑥→0 3tan2𝑥 3, (1) 2 (2) 7 (3) 5 (4) 1 Q69. 1 3 𝛼+ 3 2 2 The values of 𝛼, for which 1 1 = 0, lie in the interval 1 𝛼+ 3 3 2𝛼+ 3 3𝛼+ 1 0 (1) ( - 2, 1 ) (2) ( - 3, 0 ) (3) -3 3 (4) ( 0, 3 ) 2, 2

Q69.Let M denote the median of the following frequency distribution. Class 0 −4 4 −8 8 −12 12 −16 16 −20 Frequency 3 9 10 8 6 Then 20M is equal to : (1) 416 (2) 104 (3) 52 (4) 208 Q70. 2 cos4 x 2 sin4 x 3 + sin2 2x If f(x) = 3 + 2 cos4 x 2 sin4 x sin2 2x then 15 f ′(0) is equal to ________. 2 cos4 x 3 + 2 sin4 x sin2 2x JEE Main 2024 (30 Jan Shift 1) JEE Main Previous Year Paper (1) 0 (2) 1 (3) 2 (4) 6

Q69.Let A = {1, 2, 3, 4, 5}. Let R be a relation on A defined by xRy if and only if 4x ≤5y. Let m be the number of elements in R and n be the minimum number of elements from A × A that are required to be added to R to make it a symmetric relation. Then m + n is equal to : (1) 25 (2) 24 (3) 26 (4) 23

Q69.If the variance of the frequency distribution x c 2c 3c 4c 5c 6c is 160, then the value of c ∈N is f 2 1 1 1 1 1 (1) 7 (2) 8 (3) 5 (4) 6 and A be a 2 × 2 matrix such that AB−1 = A−1 . If BCB−1 = A and C 4 + αC 2 + βI = O,

Q69.Let [t] be the greatest integer less than or equal to t. Let A be the set of all prime factors of 2310 and . The number of one-to-one functions from A to the + f : A →Z be the function f(x) = [log2 (x2 [ x35 ])] range of f is (1) 25 (2) 24 (3) 20 (4) 120

Q69.Consider the system of linear equations 𝑥+ 𝑦+ 𝑧= 5, 𝑥+ 2𝑦+ 𝜆2𝑧= 9 and 𝑥+ 3𝑦+ 𝜆𝑧= 𝜇, where 𝜆, 𝜇∈𝑅. Then, which of the following statement is NOT correct ? (1) System has infinite number of solution if 𝜆= 1 (2) System is inconsistent if 𝜆= 1 and 𝜇≠13 and 𝜇= 13 (3) System has unique solution if 𝜆≠1 and 𝜇≠13 (4) System is consistent if 𝜆≠1 and 𝜇= 13

Q69.Let 𝑓: →𝑅→0, ∞ be strictly increasing function such that lim 𝑓7𝑥 1. Then, the value of lim 𝑓5𝑥 is 𝑥→∞ 𝑓𝑥= 𝑥→∞ 𝑓𝑥−1 equal to (1) 4 (2) 0 (3) 7 (4) 1 5

Q69.If a = lim √1+√1+x4−√2 and b = lim sin2 x , then the value of ab3 is : x→0 x4 x→0 √2−√1+cos x (1) 36 (2) 32 (3) 25 (4) 30

Q69.Let the median and the mean deviation about the median of 7 observation 170, 125, 230, 190, 210, 𝑎, 𝑏 be 170 205 and respectively. Then the mean deviation about the mean of these 7 observations is: 7 (1) 31 (2) 28 (3) 30 (4) 32 0

Q69.If the mean of the following probability distribution of a random variable X : X 0 2 4 6 8 46 is , then the variance of the distribution is P(X) a 2a a + b 2b 3b 9 (1) 173 (2) 566 27 81 (3) 151 (4) 581 27 81

Q69.The mean and standard deviation of 20 observations are found to be 10 and 2 . respectively. On rechecking, it was found that an observation by mistake was taken 8 instead of 12. The correct standard deviation is (1) 1.8 (2) 1.94 (3) √3.96 (4) √3.86

Q69.Consider 10 observation 𝑥1, 𝑥2, . .. 𝑥10, such that ∑𝑖=10 1 𝑥𝑖−𝛼= 2 and ∑𝑖=10 1 𝑥𝑖−𝛽2 = 40, where 𝛼, 𝛽 are 6 84 𝛽 positive integers. Let the mean and the variance of the observations be and respectively. The is equal to: 5 25 𝛼 (1) 2 (2) 3 2 (3) 5 (4) 1 2

Q69.If R is the smallest equivalence relation on the set {1, 2, 3, 4} such that {(1, 2), (1, 3)} ⊂R, then the number of elements in R is ______. (1) 10 (2) 12 (3) 8 (4) 15 Q70. ⎡ 2 1 2 ⎤ ⎡ 1 2 0⎤ Let A = 6 2 11 and P = 5 0 2 . The sum of the prime factors of P−1AP −2I is equal to ⎣ 3 3 2 ⎦ ⎣ 7 1 5⎦ (1) 26 (2) 27 (3) 66 (4) 23

Q70.If A is a square matrix of order 3 such that det(A) = 3 and det (adj (−4 adj (−3 adj (3 adj ((2 A)−1))))) = 2m3n , then m + 2n is equal to : (1) 2 (2) 3 (3) 6 (4) 4 JEE Main 2024 (06 Apr Shift 2) JEE Main Previous Year Paper

Q70.If 𝐴= √2 1 , 𝐵1 , 𝐶= 𝐴𝐵𝐴𝑇 and 𝑋= 𝐴𝑇𝐶2𝐴, then det 𝑋 is equal to: −1 √2 1 1 (1) 243 (2) 729 (3) 27 (4) 891

Q70.If the domain of the function 𝑓𝑥= 2𝑥+ 3 + cos-12𝑥- 1 is ( 𝛼, 𝛽], then the value of 5𝛽- 4𝛼 is equal to log𝑒 4𝑥2 + 𝑥- 3 𝑥+ 2 (1) 10 (2) 12 (3) 11 (4) 9 𝑥2𝑔𝑥𝑑𝑥

Q70.If the system of equations x + 4y −z = λ, 7x + 9y + μz = −3, 5x + y + 2z = −1 has infinitely many solutions, then (2μ + 3λ) is equal to : (1) 3 (2) -3 (3) -2 (4) 2 where a > 0 and g(x) = (f(x ∣) −|f(x)|)/2. Then the function

Q70. x + (√2 sin α)y + (√2 cos α)z = 0 If the system of equations x + (cos α)y + (sin α)z = 0 has a non-trivial solution, then α ∈(0, π2 ) is x + (sin α)y −(cos α)z = 0 equal to : (1) 11π (2) 5π 24 24 (3) 7π (4) 3π 24 4 is (α, β], then 3α + 10β is equal to:

Q70.Considering only the principal values of inverse trigonometric functions, the number of positive real values of 𝑥 satisfying tan-1 (x) + tan-1 (2x) = π is : 4 (1) More than 2 (2) 1 (3) 2 (4) 0

Q70. x + y + z = 4, The values of m, n, for which the system of equations 2x + 5y + 5z = 17, has infinitely many solutions, x + 2y + mz = n satisfy the equation: (1) m2 + n2 −mn = 39 (2) m2 + n2 −m −n = 46 (3) m2 + n2 + m + n = 64 (4) m2 + n2 + mn = 68

Q70.Let A = {1, 3, 7, 9, 11} and B = {2, 4, 5, 7, 8, 10, 12}. Then the total number of one-one maps f : A →B , such that f(1) + f(3) = 14, is : (1) 480 (2) 240 (3) 120 (4) 180

Q70.For the function f(x) = (cos x) −x + 1, x ∈R, between the following two statements (S1) f(x) = 0 for only one value of x in [0, π]. (S2) f(x) is decreasing in [0, π2 ] and increasing in [ π2 , π]. (1) Both (S1) and (S2) are correct. (2) Both (S1) and (S2) are incorrect. (3) Only (S2) is correct. (4) Only (S1) is correct.

Q70.Let the relations R1 and R2 on the set X = {1, 2, 3, … , 20} be given by R1 = {(x, y) : 2x −3y = 2} and R2 = {(x, y) : −5x + 4y = 0}. If M and N be the minimum number of elements required to be added in R1 and R2 , respectively, in order to make the relations symmetric, then M + N equals (1) 12 (2) 16 (3) 8 (4) 10 α