JEE Main Mathematics Important & Repeated Questions 2027
95 question types that recur across JEE Main Paper-1 shifts (2022–2025). JEE Main rarely repeats a question verbatim — but it reuses these templates every session. Master the pattern, not the numbers.
Sets, Relations and Functions
1. Relation properties
seen 6×2022202320242025
Let A be the set of all functions f: Z -> Z and R be a relation on A such that R = {(f, g) : f(0) = g(1) and f(1) = g(0)}. Then R is :
(1) Reflexive but neither symmetric nor transitive
(2) Symmetric but neither reflexive nor transitive
(3) Transitive but neither reflexive nor symmetric
(4) Symmetric and transitive but not reflexive
2. Range of a function
seen 5×202320242025
Let f, g : (1, infinity) -> R be defined as f(x) = (2x + 3)/(5x + 2) and g(x) = (2 - 3x)/(1 - x). If the range of the function fog : [2, 4] -> R is [alpha, beta], then 1/(beta - alpha) is equal to (1) 2 (2) 29 (3) 56 (4) 68
3. Counting relations/elements
seen 4×202320242025
The number of relations on the set A = {1, 2, 3}, containing at most 6 elements including (1, 2), which are reflexive and transitive but not symmetric, is ______
4. One-one/onto nature
seen 3×2024
The function f(x) = (x2 + 2x - 15)/(x2 - 4x + 9), x in R is
(1) both one-one and onto.
(2) one-one but not onto.
(3) onto but not one-one.
(4) neither one-one nor onto.
5. Domain & inequality sets
seen 3×20222023
Let A = {x in R : [x + 3] + [x + 4] <= 3}, B = {x in R : 3x (sumr=1infinity 3/10r)^(x-3) < 3^(-3x)}, where [t] denotes greatest integer function. Then,
(1) B subset C, A != B
(2) A intersection B = phi
(3) A = B
(4) A subset B, A != B
Complex Numbers and Quadratic Equations
6. Complex locus & distance
seen 6×2022202320242025
Let z be a complex number such that |z| = 1. If (2 + k2*z)/(k + zbar) = k*z, k belongs to R, then the maximum distance of k + i*k2 from the circle |z - (1 + 2i)| = 1 is :
(1) sqrt(3) + 1
(2) 2
(3) sqrt(5) + 1
(4) 3
7. Power sums of roots (recurrence)
seen 4×20242025
Let Pn = alphan + betan, n belongs to N. If P10 = 123, P9 = 76, P8 = 47 and P1 = 1, then the quadratic equation having roots 1/alpha and 1/beta is :
(1) x2 - x + 1 = 0
(2) x2 + x - 1 = 0
(3) x2 - x - 1 = 0
(4) x2 + x + 1 = 0
8. Purely real/imaginary condition
seen 4×2022202320242025
Among the statements
(S1): The set {z in C - {-i} : |z| = 1 and (z - i)/(z + i) is purely real} contains exactly two elements, and
(S2): The set {z in C - {-1} : |z| = 1 and (z - 1)/(z + 1) is purely imaginary} contains infinitely many elements.
(1) both are correct
(2) both are incorrect
(3) only (S1) is correct
(4) only (S2) is correct
9. Modulus equations & inequalities
seen 4×20232024
The number of distinct real roots of the equation |x + 1| |x + 3| - 4|x + 2| + 5 = 0, is __________.
10. Root conditions with parameter
seen 3×20222025
Consider the equation x2 + 4x - n = 0, where n in [20, 100] is a natural number. Then the number of all distinct values of n, for which the given equation has integral roots, is equal to (1) 5 (2) 6 (3) 7 (4) 8
11. Powers of complex numbers
seen 3×202220232024
If the set R = {(a,b) : a + 5b = 42, a, b in N} has m elements and sumn=1m (1 - i^(n!)) = x + iy, where i = sqrt(-1), then the value of m + x + y is
(1) 12
(2) 8
(3) 5
(4) 4
12. Modulus/conjugate algebra
seen 2×2024
Let z be a complex number such that |z + 2| = 1 and Im((z+1)/(z+2)) = 1/5. Then the value of |Re(conjugate(z+2))| is
(1) 2 sqrt(6)/5
(2) 24/5
(3) sqrt(6)/5
(4) (1+sqrt(6))/5
Matrices and Determinants
13. System of linear equations
seen 10×2022202320242025
If the system of linear equations
3x + y + beta*z = 3
2x + alpha*y - z = -3
x + 2y + z = 4
has infinitely many solutions, then the value of 22*beta - 9*alpha is :
(1) 49
(2) 43
(3) 37
(4) 31
14. Determinant & adjoint properties
seen 8×2022202320242025
Let a belongs to R and A be a matrix of order 3x3 such that det(A) = -4 and A + I = [[1, a, 1], [2, 1, 0], [a, 1, 2]], where I is the identity matrix of order 3x3. If det((a + 1)*adj((a - 1)*A)) is 2m * 3n, m, n belongs to {0, 1, 2, ..., 20}, then m + n is equal to :
(1) 14
(2) 15
(3) 16
(4) 17
15. Powers of a matrix / trace
seen 5×2022202320242025
Let A = [[alpha, -1], [6, beta]], alpha > 0, such that det(A) = 0 and alpha + beta = 1. If I denotes 2x2 identity matrix, then the matrix (I + A)8 is :
(1) [[4, -1], [6, -1]]
(2) [[257, -64], [514, -127]]
(3) [[766, -255], [1530, -509]]
(4) [[1025, -511], [2024, -1024]]
16. Matrix algebra identities
seen 4×202220232024
Let A be a square matrix such that AAT = I. Then (1/2) A[(A + AT)2 + (A - AT)2] is equal to Options: (1) A2 + AT (2) A3 + AT (3) A2 + I (4) A3 + I
17. Singular matrix conditions
seen 3×202220232025
The number of singular matrices of order 2, whose elements are from the set {2, 3, 6, 9}, is ______
18. Cayley-Hamilton identity
seen 2×20222024
Let A = [[2, a, 0],[1, 3, 1],[0, 5, b]]. If A3 = 4A2 - A - 21I, where I is the identity matrix of order 3x3, then 2a + 3b is equal to
(1) -9
(2) -13
(3) -12
(4) -10
Permutations and Combinations
19. Dictionary rank
seen 4×202220232024
If all the words with or without meaning made using all the letters of the word "NAGPUR" are arranged as in a dictionary, then the word at 315th position in this arrangement is :
(1) NRAGPU
(2) NRAPGU
(3) NRAGUP
(4) NRAPUG
20. Multiset arrangements
seen 2×20232025
The number of sequences of ten terms, whose terms are either 0 or 1 or 2, that contain exactly five 1s and exactly three 2s, is equal to :
(1) 45
(2) 360
(3) 1820
(4) 2520
21. Constrained selection
seen 2×20232025
From a group of 7 batsmen and 6 bowlers, 10 players are to be chosen for a team, which should include atleast 4 batsmen and atleast 4 bowlers. One batsmen and one bowler who are captain and vice-captain respectively of the team should be included. Then the total number of ways such a selection can be made, is
(1) 135
(2) 145
(3) 155
(4) 165
22. Range count by divisibility
seen 2×20232024
Let A = {n in [100, 700] intersect N: n is neither a multiple of 3 nor a multiple of 4}. Then the number of elements in A is
(1) 280
(2) 290
(3) 300
(4) 310
23. Numbers from digits (divisibility)
seen 2×20222024
The number of 3-digit numbers, formed using the digits 2, 3, 4, 5 and 7, when the repetition of digits is not allowed, and which are not divisible by 3, is equal to __________.
24. Counting functions
seen 2×2022
The total number of functions, f : {1, 2, 3, 4} -> {1, 2, 3, 4, 5, 6} such that f(1) + f(2) = f(3), is equal to :
(A) 60
(B) 90
(C) 108
(D) 126
Binomial Theorem and Its Simple Applications
25. Term independent of x
seen 4×202220242025
The term independent of x in the expansion of ((x + 1)/(x2/3 + 1 - x1/3) - (x - 1)/(x - x1/2))10, x > 1, is :
(1) 150
(2) 210
(3) 120
(4) 240
26. Remainder of large power
seen 3×202220232025
The remainder when ((64)^(64))^(64) is divided by 7 is equal to
(1) 1
(2) 3
(3) 4
(4) 6
27. Coefficient of xk
seen 3×2023
The coefficient of x18 in the expansion of (x4 - 1/x3)15 is ______
28. Ratio of terms from both ends
seen 2×20232025
In the expansion of ( cbrt(2) + 1/cbrt(3) )n, n in N, if the ratio of 15th term from the beginning to the 15th term from the end is 1/6, then the value of nC3 is (1) 1040 (2) 2300 (3) 4060 (4) 4960
29. Sum of r-weighted binomial coefficients
seen 2×20232024
Let alpha = sumr=0n (4r2 + 2r + 1) C(n, r) and beta = (sumr=0n C(n, r)/(r + 1)) + 1/(n + 1). If 140 < 2 alpha/beta < 281, then the value of n is __________.
Sequence and Series
30. Determine a GP
seen 5×20232024
In an increasing geometric progression of positive terms, the sum of the second and sixth terms is 70/3 and the product of the third and fifth terms is 49. Then the sum of the 4th, 6th and 8th terms is equal to :
(1) 78
(2) 84
(3) 91
(4) 96
31. Infinite GP sum
seen 3×20222024
Let ABC be an equilateral triangle. A new triangle is formed by joining the middle points of all sides of the triangle ABC and the same process is repeated infinitely many times. If P is the sum of perimeters and Q is the sum of areas of all the triangles formed in this process, then :
(1) P = 36 sqrt(3) Q2
(2) P2 = 6 sqrt(3) Q
(3) P2 = 36 sqrt(3) Q
(4) P2 = 72 sqrt(3) Q
32. Series sum via nth term
seen 2×20232025
1 + 3 + 52 + 7 + 92 + ... upto 40 terms is equal to (1) 33980 (2) 43890 (3) 40870 (4) 41880
33. Triangular number arrangement
seen 2×2024
An arithmetic progression is written in the following way:
2
5 8
11 14 17
20 23 26 29
_ _ _ _ _ _ _ _ _ _
_ _ _ _ _ _ _ _ _ _
The sum of all the terms of the 10th row is __________.
34. Arithmetico-geometric series
seen 2×20222024
If S(x) = (1+x) + 2(1+x)2 + 3(1+x)3 + ... + 60(1+x)60, x != 0, and (60)2 S(60) = a(b)b + b, where a, b ∈ N, then (a + b) equal to _______.
35. Logarithms with progressions
seen 2×2023
For three positive integers p, q, r, xpq2 = yqr = zp2 r and r = pq + 1 such that 3, 3 logy x, 3 logz y, 7 logx z are in A.P. with common difference 1/2. Then r - p - q is equal to Options: 1) -6 2) 12 3) 2 4) 6
36. AP surd telescoping sum
seen 2×2023
Let a1, a2, a3, ..., an be n positive consecutive terms of an arithmetic progression. If d > 0 is its common difference, then limn->infinity sqrt(d/n) ( 1/(sqrt(a1)+sqrt(a2)) + 1/(sqrt(a2)+sqrt(a3)) + ... + 1/(sqrt(a_(n-1))+sqrt(an)) ) is
(1) sqrt(d)
(2) 1/sqrt(d)
(3) 0
(4) 1
Limit, Continuity and Differentiability
37. Count non-diff/discontinuity points
seen 6×2022202320242025
Let m and n be the number of points at which the function f(x) = max{ x, x3, x5, ..., x21 }, x in R, is not differentiable and not continuous, respectively. Then m + n is equal to ______
38. Standard limit evaluation
seen 4×202220242025
limx->0^+ [tan(5 (x)^(1/3)) loge(1 + 3x2)] / [(tan-1(3 sqrt(x)))2 (e^(5 (x)^(4/3)) - 1)] is equal to
(1) 1
(2) 1/3
(3) 5/3
(4) 1/15
39. Local extrema of a cubic
seen 4×202220242025
If the function f(x) = 2*x3 - 9*a*x2 + 12*a2*x + 1, where a > 0, attains its local maximum and local minimum values at p and q, respectively, such that p2 = q, then f(3) is equal to :
(1) 37
(2) 55
(3) 10
(4) 23
40. Optimization word problem
seen 4×202220232024
Let A be the region enclosed by the parabola y2 = 2x and the line x = 24. Then the maximum area of the rectangle inscribed in the region A is __________.
41. Composite differentiation at a point
seen 3×20232024
Suppose for a differentiable function h, h(0) = 0, h(1) = 1 and h'(0) = h'(1) = 2. If g(x) = h(ex) eh(x), then g'(0) is equal to :
(1) 3
(2) 4
(3) 5
(4) 8
42. Limit fixing parameters (series)
seen 2×2025
For alpha, beta, gamma belongs to R, if limx->0 (x2*sin(alpha*x) + (gamma - 1)*ex2) / (sin(2x) - beta*x) = 3, then beta + gamma - alpha is equal to :
(1) -1
(2) 4
(3) 6
(4) 7
43. Monotonicity intervals
seen 2×2024
The interval in which the function f(x) = xx, x > 0, is strictly increasing is
(1) [1/e, infinity)
(2) (0, 1/e]
(3) [1/e2, 1)
(4) (0, infinity)
44. Count critical/maxima points
seen 2×2024
The number of critical points of the function f(x) = (x - 2)^(2/3) (2x + 1) is
(1) 0
(2) 1
(3) 2
(4) 3
45. Root counting via monotonicity
seen 2×2024
Consider the function f: [1/2, 1] -> R defined by f(x) = 4 sqrt(2) x3 - 3 sqrt(2) x - 1. Consider the statements (I) The curve y = f(x) intersects the x-axis exactly at one point. (II) The curve y = f(x) intersects the x-axis at x = cos(pi/12). Then Options: (1) Both (I) and (II) are correct. (2) Both (I) and (II) are incorrect. (3) Only (I) is correct. (4) Only (II) is correct.
46. Absolute extrema on an interval
seen 2×20222025
Let x = -1 and x = 2 be the critical points of the function f(x) = x3 + a x2 + b loge|x| + 1, x != 0. Let m and M respectively be the absolute minimum and the absolute maximum values of f in the interval [-2, -1/2]. Then |M + m| is equal to (Take loge 2 = 0.7):
(1) 19.8
(2) 20.9
(3) 21.1
(4) 22.1
47. xn sin(1/x) continuity/diff
seen 2×20232024
If f(x) = { x3 sin(1/x), x != 0 ; 0, x = 0 }, then
(1) f''(0) = 0
(2) f''(2/pi) = (24 - pi2)/(2 pi)
(3) f''(0) = 1
(4) f''(2/pi) = (12 - pi2)/(2 pi)
48. Limit of power-sum ratios
seen 2×20222024
limn->∞ [ (12 - 1)(n-1) + (22 - 2)(n-2) + ... + ((n-1)2 - (n-1))·1 ] / [ (13 + 23 + ... + n3) - (12 + 22 + ... + n2) ] is equal to :
(1) 1/2
(2) 1/3
(3) 2/3
(4) 3/4
49. Extremum value of a function
seen 2×20222024
If the function f(x) = (1/x)2x; x > 0 attains the maximum value at x = 1/e then :
(1) e^π > πe
(2) e^π < πe
(3) e2π < (2π)e
(4) (2e)^π > π(2e)
50. Continuity: find parameter
seen 2×20222024
For a, b > 0, let f(x) = { (tan((a+1)x) + b tan x)/x , x < 0 ; 3 , x = 0 ; (sqrt(ax + b2 x2) - sqrt(ax))/(b sqrt(a) x sqrt(x)) , x > 0 } be a continuous function at x = 0. Then b/a is equal to :
(1) 6
(2) 5
(3) 4
(4) 8
51. Implicit differentiation at a point
seen 2×20222023
If 2 xy + 3 yx = 20, then dy/dx at (2, 2) is equal to:
(1) -((3 + loge 16)/(4 + loge 8))
(2) -((3 + loge 4)/(2 + loge 8))
(3) -((2 + loge 8)/(3 + loge 4))
(4) -((3 + loge 8)/(2 + loge 4))
Integral Calculus
52. Area between curve and line
seen 7×2022202320242025
If the area of the region bounded by the curves y = 4 - x2/4 and y = (x - 4)/2 is equal to alpha, then 6 alpha equals
(1) 210
(2) 220
(3) 240
(4) 250
53. Area with modulus/min-max curves
seen 5×2022202320242025
If the area of the region {(x, y): |4 - x2| <= y <= x2, y <= 4, x >= 0} is (80*sqrt(2)/alpha - beta), alpha, beta belongs to N, then alpha + beta is equal to ______.
54. Definite integral by symmetry (King)
seen 5×2022202320242025
The value of integral from -1 to 1 of [ (1 + sqrt(|x| - x)) ex + (sqrt(|x| - x)) e^(-x) ] / (ex + e^(-x)) dx is equal to (1) 2 + 2 sqrt(2)/3 (2) 3 - 2 sqrt(2)/3 (3) 1 - 2 sqrt(2)/3 (4) 1 + 2 sqrt(2)/3
55. Integral of GIF/modulus function
seen 5×2022202320242025
Let [.] denote the greatest integer function. If integral from 0 to e3 of [1/ex-1] dx = alpha - loge(2), then alpha3 is equal to ______.
56. Indefinite integral I(a) given, find I(b)
seen 4×20232024
Let I(x) = integral of 6/(sin2 x (1 - cot x)2) dx. If I(0) = 3, then I(pi/12) is equal to
(1) 2 sqrt(3)
(2) 3 sqrt(3)
(3) 6 sqrt(3)
(4) sqrt(3)
57. Area involving a circle
seen 3×20232024
The area of the region in the first quadrant inside the circle x2 + y2 = 8 and outside the parabola y2 = 2x is equal to :
(1) pi - 2/3
(2) pi/2 - 2/3
(3) pi - 1/3
(4) pi/2 - 1/3
58. Solve integral equation for f
seen 3×20222025
Let f : [0, infinity) -> R be a differentiable function such that f(x) = 1 - 2x + integral from 0 to x of e^(x - t) f(t) dt for all x in [0, infinity). Then the area of the region bounded by y = f(x) and the coordinate axes is (1) 2 (2) sqrt(2) (3) 1/2 (4) sqrt(5)
59. Definite integral by substitution
seen 3×202220232024
integral0pi/4 (cos2 x sin2 x)/(cos3 x + sin3 x)2 dx is equal to
(1) 1/3
(2) 1/6
(3) 1/9
(4) 1/12
60. Reduction-formula integral
seen 2×2024
Let rk = [integral01 (1 - x7)k dx] / [integral01 (1 - x7)k+1 dx], k in N. Then the value of sumk=110 1/(7(rk - 1)) is equal to ________
61. Integrate to given form, find constants
seen 2×2024
If ∫ 1/(a2 sin2 x + b2 cos2 x) dx = (1/12) tan-1(3 tan x) + constant, then the maximum value of a sin x + b cos x, is :
(1) sqrt(42)
(2) sqrt(39)
(3) sqrt(40)
(4) sqrt(41)
Differential Equations
62. Linear ODE (integrating factor)
seen 7×2022202320242025
Let y = y(x) be the solution curve of the differential equation x(x2 + ex) dy + (ex (x - 2) y - x3) dx = 0, x > 0, passing through the point (1, 0). Then y(2) is equal to
(1) 4/(4 - e2)
(2) 2/(2 - e2)
(3) 4/(4 + e2)
(4) 2/(2 + e2)
63. Variable-separable ODE
seen 4×20222024
If the solution y(x) of the given differential equation (ey + 1) cos x dx + ey sin x dy = 0 passes through the point (π/2, 0), then the value of ey(π/6) is equal to _______.
64. ODE whose solution is a circle
seen 2×20222024
Suppose the solution of the differential equation dy/dx = ((2 + α)x - βy + 2)/(βx - 2αy - (βγ - 4α)) represents a circle passing through origin. Then the radius of this circle is :
(1) sqrt(17)/2
(2) 2
(3) sqrt(17)
(4) 1/2
65. Integral-equation to linear ODE
seen 2×2023
Let f be a differentiable function such that x2 f(x) - x = 4 ∫0x t f(t) dt, f(1) = 2/3. Then 18 f(3) is equal to
(1) 180
(2) 150
(3) 160
(4) 210
66. Homogeneous ODE
seen 2×20222023
The slope of tangent at any point (x, y) on a curve y = y(x) is (x2 + y2)/(2xy), x > 0. If y(2) = 0, then a value of y(8) is
(1) -4 sqrt(2)
(2) -2 sqrt(3)
(3) 2 sqrt(3)
(4) 4 sqrt(3)
Co-ordinate Geometry
67. Reflection of a point in a line
seen 3×2024
If the image of the point (-4, 5) in the line x + 2y = 2 lies on the circle (x + 4)2 + (y - 3)2 = r2, then r is equal to :
(1) 1
(2) 2
(3) 3
(4) 4
68. Orthocentre from three lines
seen 2×2025
Let the three sides of a triangle are on the lines 4x - 7y + 10 = 0, x + y = 5 and 7x + 4y = 15. Then the distance of its orthocentre from the orthocentre of the triangle formed by the lines x = 0, y = 0 and x + y = 1 is (1) 20 (2) 5 (3) sqrt(5) (4) sqrt(20)
69. Externally touching circles
seen 2×20242025
Let C1 be the circle in the third quadrant of radius 3, that touches both coordinate axes. Let C2 be the circle with centre (1, 3) that touches C1 externally at the point (alpha, beta). If (beta - alpha)2 = m/n, gcd(m, n) = 1, then m + n is equal to
(1) 9
(2) 13
(3) 22
(4) 31
70. Parabola from focus & directrix
seen 2×20232025
Let P be the parabola, whose focus is (-2, 1) and directrix is 2x + y + 2 = 0. Then the sum of the ordinates of the points on P, whose abscissa is -2, is
(1) 5/2
(2) 3/4
(3) 3/2
(4) 1/4
71. Hyperbola focal-distance product
seen 2×2024
The length of the latus rectum and directrices of a hyperbola with eccentricity e are 9 and x = ±4/sqrt(3), respectively. Let the line y - sqrt(3) x + sqrt(3) = 0 touch this hyperbola at (x0, y0). If m is the product of the focal distances of the point (x0, y0), then 4e2 + m is equal to _______.
72. Parabola focal chord
seen 2×20222025
Let the focal chord PQ of the parabola y2 = 4x make an angle of 60 degrees with the positive x-axis, where P lies in the first quadrant. If the circle, whose one diameter is PS, S being the focus of the parabola, touches the y-axis at the point (0, alpha), then 5*alpha2 is equal to :
(1) 15
(2) 20
(3) 25
(4) 30
73. Circle centre from diameters
seen 2×20222024
Equations of two diameters of a circle are 2x - 3y = 5 and 3x - 4y = 7. The line joining the points (-22/7, -4) and (-1/7, 3) intersects the circle at only one point P(alpha, beta). Then, 17 beta - alpha is equal to _______.
74. Common tangent ellipse-hyperbola
seen 2×2022
For the hyperbola H : x2 - y2 = 1 and the ellipse E : x2/a2 + y2/b2 = 1, a > b > 0, let (1) the eccentricity of E be reciprocal of the eccentricity of H, and (2) the line y = sqrt(5/2) x + K be a common tangent of E and H. Then 4(a2 + b2) is equal to ______.
Three Dimensional Geometry
75. Shortest distance between skew lines
seen 11×2022202320242025
Let the shortest distance between the lines (x - 3)/3 = (y - alpha)/(-1) = (z - 3)/1 and (x + 3)/(-3) = (y + 7)/2 = (z - beta)/4 be 3 sqrt(30). Then the positive value of 5 alpha + beta is (1) 40 (2) 42 (3) 46 (4) 48
76. Foot of perpendicular to a line (3D)
seen 6×202220242025
Let the vertices Q and R of the triangle PQR lie on the line (x + 3)/5 = (y - 1)/2 = (z + 4)/3, QR = 5 and the coordinates of the point P be (0, 2, 3). If the area of the triangle PQR is m/n then :
(1) 5*m - 21*sqrt(2)*n = 0
(2) 5*m - 2*sqrt(21)*n = 0
(3) m - 5*sqrt(21)*n = 0
(4) 2*m - 5*sqrt(21)*n = 0
77. Line meeting two given lines
seen 2×20242025
Let the line L pass through (1, 1, 1) and intersect the lines (x-1)/2 = (y+1)/3 = (z-1)/4 and (x-3)/1 = (y-4)/2 = z/1. Then, which of the following points lies on the line L?
(1) (4, 22, 7)
(2) (7, 15, 13)
(3) (10, -29, -50)
(4) (5, 4, 3)
78. Image of a point in a plane
seen 2×2023
Let the image of the point P(1, 2, 3) in the plane 2x - y + z = 9 be Q. If the coordinates of the point R are (6, 10, 7), then the square of the area of the triangle PQR is ______
79. Line-plane intersection
seen 2×2023
Let P be the point of intersection of the line (x+3)/3 = (y+2)/1 = (1-z)/2 and the plane x + y + z = 2. If the distance of the point P from the plane 3x - 4y + 12z = 32 is q, then q and 2q are the roots of the equation
(1) x2 + 18x + 72 = 0
(2) x2 + 18x - 72 = 0
(3) x2 - 18x - 72 = 0
(4) x2 - 18x + 72 = 0
80. Point-plane distance along a line
seen 2×20222023
The distance of the point (-1, 9, -16) from the plane 2x + 3y - z = 5 measured parallel to the line (x+4)/3 = (2-y)/4 = (z-3)/12 is Options: 1) 31 2) 26 3) 13 sqrt(2) 4) 20 sqrt(2)
Vector Algebra
81. Solve for unknown vector
seen 5×202220232024
Let a = 2 i - 3 j + 4 k, b = 3 i + 4 j - 5 k and a vector c be such that a x (b + c) + b x c = i + 8 j + 13 k. If a . c = 13, then (24 - b . c) is equal to ________
82. Coplanarity (triple product)
seen 2×20222023
Let the position vectors of the points A, B, C and D be 5 i^ + 5 j^ + 2 lambda k^, i^ + 2 j^ + 3 k^, -2 i^ + lambda j^ + 4 k^ and -i^ + 5 j^ + 6 k^. Let the set S = {lambda in R : the points A, B, C and D are coplanar}. Then sumlambda in S (lambda + 2)2 is equal to
(1) 41
(2) 13
(3) 37/2
(4) 25
83. Dot-cross magnitude relation
seen 2×20222023
Let a and b be two vectors such that |a| = sqrt(14), |b| = sqrt(6) and |a x b| = sqrt(48). Then (a . b)2 is equal to ______.
Statistics and Probability
84. Bayes' theorem
seen 4×202220232024
A company has two plants A and B to manufacture motorcycles. 60% motorcycles are manufactured at plant A and the remaining are manufactured at plant B. 80% of the motorcycles manufactured at plant A are rated of the standard quality, while 90% of the motorcycles manufactured at plant B are rated of the standard quality. A motorcycle picked up randomly from the total production is found to be of the standard quality. If p is the probability that it was manufactured at plant B, then 126p is
(1) 56
(2) 64
(3) 66
(4) 54
85. Correcting SD for wrong observation
seen 2×20242025
The mean and standard deviation of 100 observations are 40 and 5.1, respectively. By mistake one observation is taken as 50 instead of 40. If the correct mean and the correct standard deviation are mu and sigma respectively, then 10(mu + sigma) is equal to
(1) 451
(2) 449
(3) 447
(4) 445
86. Hypergeometric variance
seen 2×20242025
A box contains 10 pens of which 3 are defective. A sample of 2 pens is drawn at random and let X denote the number of defective pens. Then the variance of X is (1) 3/5 (2) 11/15 (3) 2/15 (4) 28/75
87. Unknowns from mean & variance
seen 2×2024
Let a, b, c in N and a < b < c. Let the mean, the mean deviation about the mean and the variance of the 5 observations 9, 25, a, b, c be 18, 4 and 136/5, respectively. Then 2a + b - c is equal to __________.
88. Variance of frequency distribution
seen 2×2023
If the mean of the frequency distribution
Class: 0-10, 10-20, 20-30, 30-40, 40-50
Frequency: 2, 3, x, 5, 4
is 28, then its variance is ____.
89. Two-dice inequality probability
seen 2×20222023
Let N denote the sum of the numbers obtained when two dice are rolled. If the probability that 2N < N! is m/n, where m and n are coprime, then 4m - 3n is equal to
(1) 12
(2) 8
(3) 6
(4) 10
90. Binomial probability computation
seen 2×20222023
A pair of dice is thrown 5 times. For each throw, a total of 5 is considered a success. If the probability of at least 4 successes is k/311, then k is equal to
(1) 123
(2) 75
(3) 164
(4) 82
91. Binomial mean & variance conditions
seen 2×2022
If the sum and the product of mean and variance of a binomial distribution are 24 and 128 respectively, then the probability of one or two successes is :
(A) 33/232
(B) 33/229
(C) 33/228
(D) 33/227
Trigonometry
92. Evaluate inverse-trig expression
seen 4×202220232025
Considering the principal values of the inverse trigonometric functions, sin-1( (sqrt(3)/2) x + (1/2) sqrt(1 - x2) ), -1/2 < x < 1/sqrt(2), is equal to (1) pi/4 + sin-1 x (2) pi/6 + sin-1 x (3) 5pi/6 - sin-1 x (4) -5pi/6 - sin-1 x
93. Number of solutions
seen 3×20222025
If theta belongs to [-2*pi, 2*pi], then the number of solutions of 2*sqrt(2)*cos2(theta) + (2 - sqrt(6))*cos(theta) - sqrt(3) = 0, is equal to :
(1) 8
(2) 6
(3) 10
(4) 12
94. Heights and distances
seen 3×20222023
From the top A of a vertical wall AB of height 30 m, the angles of depression of the top P and bottom Q of a vertical tower PQ are 15 degrees and 60 degrees respectively. B and Q are on the same horizontal level. If C is a point on AB such that CB = PQ, then the area (in m2) of the quadrilateral BCPQ is equal to
(1) 600(sqrt(3) - 1)
(2) 300(sqrt(3) - 1)
(3) 300(sqrt(3) + 1)
(4) 200(3 - sqrt(3))
95. Solve inverse-trig equation
seen 2×20222024
For n in N, if cot-1 3 + cot-1 4 + cot-1 5 + cot-1 n = pi/4, then n is equal to ________