NDA Mathematics 18 April 2021
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Sun, Apr 18, 2021 8:30 AM
Mathematics
What is C(n, 1) + C(n, 2) + _ _ _ _ _ + C(n, n) equal to
View Question What is the sum of the coefficients of first and last terms in the expansion of (1 + x)2n, where n is a natural number?
View Question If the first term of an AP is 2 and the sum of the first five terms is equal to one-fourth of the sum of the next five t
View Question Consider the following statements:
1. If each term of a GP is multiplied by same non-zero number, then the resulting se
View Question How many 5-digit prime numbers can be formed using the digits 1, 2, 3, 4, 5 if the repetition of digits is not allowed?
View Question If f(x + 1) = x2 - 3x + 2, then what is f(x) equal to?
View Question If x2, x, -8 are in AP, then which one of the following is correct?
View Question The third term of a GP is 3. What is the product of its first five terms?
View Question The element in the ith row and the jth column of a determinant of third order is equal to 2(i + j). What is the value of
View Question With the numbers 2, 4, 6, 8, all the possible determinants with these four different elements are constructed. What is t
View Question What is the radius of the circle 4x2 + 4y2 - 20x + 12y - 15 = 0?
View Question A parallelogram has three consecutive vertices (-3, 4), (0, -4) and (5, 2). The fourth vertex is
View Question If the lines y + px = 1 and y - qx = 2 are perpendicular, then which one of the following is correct?
View Question If A, B and C are in AP, then the straight line Ax + 2By + C = 0 will always pass through a fixed point. The fixed point
View Question If the image of the point (-4, 2) by a line mirror is (4, -2), then what is the equation of the line mirror?
View Question $\rm tan^{-1}x+cot^{-1}x=\frac{\pi}{2}$ holds, when
View Question If $\tan A=\dfrac{1}{7}$, then what is cos 2A equal to?
View Question The sides of a triangle are m, n and $\rm \sqrt{m^2+n^2+mn}$. What is the sum of the acute angles of the triangle?
View Question What is the area of the triangle ABC with sides a = 10cm and c = 4cm angle B = 30°?
View Question Consider the following statements:
1. A = {1, 3, 5} and B = {2, 4, 7} are equivalent sets.
2. A = {1, 5, 9} and B = {1
View Question Consider the following statements:
1. The null set is a subset of every set.
2. Every set is a subset of itself.
3. I
View Question Let R be a relation defined as xRy if and only if 2x + 3y = 20, where x, y ∈ N. How many elements of the form (x, y
View Question Consider the following statements:
1. A function f : Z → Z, defined by f(x) = x + 1, is one-one as well as onto.
View Question Consider the following in respect of a complex number z:
1. $\rm {\overline{\left(z^{-1}\right)}}=(\bar{z})^{-1}$
View Question 1. The difference of Z and its conjugate is an imaginary number.
2. The sum of Z and its conjugate is a real number.
View Question What is the modulus of the complex number i2n + 1(-i)2n - 1, where n ∈ N and i = √-1?
View Question If α and β are the roots of the equation 4x2 + 2x - 1 = 0, then which one of the following is correct?
View Question If one root of 5x2 + 26x + k = 0 is reciprocal of the other, then what is the value of k?
View Question In how many ways can a team of 5 players be selected from 8 players so as not to include a particular player?
View Question What is the coefficient of the middle term in the expansion of (1 + 4x + 4x2)5?
View Question If $\rm tan\:x=-\dfrac{3}{4}$ and x is in the second quadrant, then what is the value of sin x ⋅ cos x?
View Question What is the value of the following?
$\rm cosec\left(\dfrac{7\pi}{6}\right)sec\left(\dfrac{5\pi}{3}\right)$
View Question If the determinant $\left| {\begin{array}{*{20}{c}} x&1&3\\ 0&0&1\\ 1&x&4 \end{array}} \rig
View Question What is the value of the following?
tan 31° tan 33° tan 35° _ _ _ _ _ tan 57° tan 59°
View Question If
$f(x)=\left|\begin{array}{ccc}1 & 1 & x+1 \\ 2 x & x(x-1) & x(x+1) \\ 3 x(x-1) & 2(x-1)(x-2) & x(x+1)(x-1)\end{
View Question The equation $sin^{-1}x-cos^{-1}x=\frac{\pi}{6}$ has
View Question What is the value of the following?
(sin 24° + cos 66°)(sin 24° - cos 66°)
View Question A chord subtends an angle 120° at the centre of a unit circle. What is the length of the chord?
View Question What is (1 + cot θ - cosec θ)(1 + tan θ + sec θ) equal to?
View Question What is $\rm \frac{1+tan^2\theta}{1+cot^2\theta}-\left(\frac{1-tan\theta}{1-cot\theta}\right)^2$equal to?
View Question What is the interior angle of a regular octagon of side length 2 cm?
View Question If 7 sinθ + 24 cosθ = 25, then what is the value of (sin θ + cos θ)?
View Question A ladder 6 m long reaches a point 6 m below the top of a vertical flagstaff. From the foot of the ladder, the elevation
View Question The shadow of a tower is found to be x meter longer, when the angle of elevation of the sun changes from 60° to 45°. If
View Question If 3cosθ = 4sinθ, then what is the value of tan (45° + θ)?
View Question The smallest positive integer n for which
$\rm \left(\frac{1-i}{1+i}\right)^{n^2}=1$
where i = √-1, is
View Question The value of x, satisfying the equation $log_{cos x} ~sin x = 1$, where $0<x<\dfrac{\pi}{2}$, is
View Question If Δ is the value of the determinant
$\left| {\begin{array}{*{20}{c}} {{a_1}}&{{b_1}}&{{c_1}}\\ {{a_2}}&am
View Question If C0, C1, C2, _ _ _ _ _, Cn are the coefficients in the expansion of (1 + x)n, then what is the value of C1 + C2 + C3 +
View Question If a + b + c = 4 and ab + bc + ca = 0, then what is the value of the following determinant?
$\left| {\begin{array}{*{20
View Question The number of integer values of k, for which the equation 2sinx = 2k + 1 has a solution, is
View Question If a1, a2, a3, _ _ _ _ _, a9 are in GP, then what is the value of the following determinant?
$\left| {\begin{array}{*{2
View Question If the roots of the quadratic equation x2 + 2x + k = 0 are real, then
View Question If n = 100!, then what is the value of the following?
$\rm \dfrac{1}{log_2n}+\dfrac{1}{log_3n}+\dfrac{1}{log_4n}+{.....
View Question If Z = 1 + i, where i = √-1, then what is the modulus of $\rm z+\frac{2}{z}?$
View Question If A and B are two matrices such that AB is of order n × n, then which one of the following is correct?
View Question How many matrices of different orders are possible with elements comprising all prime numbers less than 30?
View Question Let $A = \left| {\begin{array}{*{20}{c}} p&q\\ r&s \end{array}} \right|$
where p, q, r and s are any four
View Question If A and B are square matrices of order 2 such that det(AB) = det(BA), then which one of the following is correct?
View Question What is cot 2x cot 4x - cot 4x cot 6x - cot 6x cot 2x equal to
View Question If M is the mean of n observations x1 - k, x2 - k, x3 - k, _ _ _, xn - k, where k is any real number, then what is the m
View Question What is the sum of deviations of the variate values 73, 85, 92, 105, 120 from their mean?
View Question Let x be the HM and y be the GM of two positive numbers m and n. If 5x = 4y, then which one of the following is correct?
View Question If the mean of a frequency distribution is 100 and the coefficient of variation is 45%, then what is the value of the va
View Question Let two events A and B be such that P(A) = L and P(B) = M. Which one of the following is correct?
View Question For which of the following sets of numbers do the mean, median and mode have the same value?
View Question The mean of 12 observations is 75. If two observation are discarded, then the mean of the remaining observations is 65.
View Question If k is one of the roots of the equation x(x + 1) + 1 = 0, then what is its other root?
View Question The geometric mean of a set of observations is computed as 10. The geometric mean obtained when each observations xi is
View Question If $\rm P(A\cup B)=\dfrac{5}{6}, P(A\cap B)=\dfrac{1}{3}\:and\:P(\bar A)=\dfrac{1}{2}$, then which of the following
View Question The average of a set of 15 observations is recorded, but later it is found that for one observation, the digit in the te
View Question A coin is tossed twice. If E and F denote occurrence of head on first toss and second toss respectively, then what is P(
View Question In a binomial distribution, the mean is $\dfrac{2}{3}$ and variance is $\dfrac{5}{9}$. What is the probability that
View Question If the mode of the scores 10, 12, 13, 15, 15, 13, 12, 10, x is 15, then what is the value of x?
View Question If A and B are two events such that $\rm P(A)=\dfrac{3}{4} \:and\: P(B)=\dfrac{5}{8}$, then consider the following
View Question What is the derivative of ex with respect to xe?
View Question If a differentiable function f(x) satisfies $\mathop {\lim }\limits_{x \to - 1} \dfrac{f(x)+1}{x^2-1}=-\dfrac{3}{2}
View Question If the function $\rm f\left( x \right) = \left\{ {\begin{array}{*{20}{c}} {a + bx,\;\;}&{x < 1}\\ {5,}&{
View Question Consider the following statements in respect of the function f(x) = sin x:
1. f(x) increases in the interval (0, π
View Question What is the domain of the function f(x) = 3x?
View Question If the general solution of a differential equation is y2 + 2cy - cx + c2 = 0, where c is an arbitrary constant, then wha
View Question What is the degree of the following differential equation?
$\rm x=\sqrt{1+\frac{d^2y}{dx^2}}$
View Question Which one of the following differential equations has the general solution y = aex + be-x?
View Question What is the solution of the following differential equation?
$\rm \ln\left(\frac{dy}{dx}\right)+y = x$
View Question What is $\rm \int e^{\left(2\ln x+\ln x^2\right)}dx$ equal to?
View Question Consider the following measures of central tendency for a set of N numbers:
1. Arithmetic mean.
2. Geometric mean.
Wh
View Question The numbers of Science, Arts and Commerce graduates working in a company are 30, 70 and 50 respectively. If these figure
View Question For a histogram based on a frequency distribution with unequal class intervals, the frequency of a class should be propo
View Question The co-efficient of correlation is independent of:
View Question The following tables gives the frequency distribution of number of peas per pea pod of 198 pods:
Number of
View Question If $\rm\mathop {\lim }\limits_{x \to a} \frac{a^x -x^a}{x^x -a^a}= - 1$, then what is the value of a?
View Question A particle starts from origin with a velocity (in m/s) given by the equation $\rm \frac{dx}{dt}=x+1$. The time (in secon
View Question What is $\rm \int_0^a \frac{f(a-x)}{f(x)+f(a-x)}\ dx $ equal to?
View Question What is $\rm\mathop {\lim }\limits_{x \to 2}\frac{x^3 + x^2}{x^2 + 3x + 2}$ equal to?
View Question If $\rm \int_0^a \left[f(x)+f(-x)\right]dx=\int_{-a}^{\ \ a} g(x)\ dx $, then what is g(x) equal to?
View Question What is the area bounded by $\rm y=\sqrt{16-x^2}$, y ≥ 0 and the x-axis?
View Question The curve y = -x3 + 3x2 + 2x - 27 has the maximum slope at:
View Question A 24 cm long wire is bent to form a triangle with one of the angles as 60°. What is the altitude of the triangle having
View Question If f(x) = e|x|, then which one of the following is correct?
View Question What is $\rm \int \frac{dx}{\sec x+\tan x}$ equal to?
View Question What is $\int \dfrac{dx}{sec^2({tan}^{-1}x)}$ equal to?
View Question If x + y = 20 and P = xy, then what is the maximum value of P?
View Question What is the derivative of sin(ln x) + cos(ln x) with respect to x at x = e?
View Question If x = et cost and y = et sint, then what is $\dfrac{dx}{dy}$ at t = 0 equal to?
View Question What is the maximum value of sin 2x ⋅ cos 2x?
View Question Consider the following statements in respect of the points (p, p - 3), (q + 3, q) and (6, 3):
1. The points lie on a st
View Question What is the acute angle between the lines x - 2 = 0 and √3x - y - 2 = 0?
View Question The point of intersection of diagonals of a square ABCD is at the origin and one of its vertices is at A(4, 2). What is
View Question If any point on a hyperbola is (3tan θ, 2sec θ), then what is the eccentricity of the hyperbola?
View Question Consider the following with regard to eccentricity (e) of a conic section:
1. e = 0 for circle
2. e = 1 for parabola
View Question What is the angle between the two lines having direction ratios (6, 3, 6) and (3, 3, 0)?
View Question If l, m, n are the direction cosines of the line x - 1 = 2(y + 3) = 1 - z, then what is l4 + m4 + n4 equal to?
View Question What is the projection of the line segment joining A(1, 7, -5) and B(-3, 4, -2) on y-axis?
View Question What is the number of possible values of k for which the line joining the points (k, 1, 3) and (1, -2, k + 1) also passe
View Question The foot of the perpendicular drawn from the origin to the plane x + y + z = 3 is
View Question A vector $\vec r=a \hat i+b \hat j$ is equally inclined to both x and y axes. If the magnitude of the vector is 2 u
View Question Consider the following statements in respect of a vector $\vec c=\vec a+\vec b$, where $|\vec a|=|\vec b|\ne0$:
1. 
View Question If $\vec a \:and\: \vec b$ are two vectors such that $|\vec a + \vec b|= |\vec a - \vec b|=4,$ then which one
View Question If $\vec a, \vec b\:and \: \vec c$ are coplanar, then what is $(2\vec a\times 3\vec b)\cdot4\vec c+(5\vec b\ti
View Question Consider the following statements:
1. The cross product of two unit vectors is always a unit vector.
2. The dot produc
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