If P = \left[ {\matrix{
1 & 0 \cr
{{1 \over 2}} & 1 \cr
} } \right], then P50 is :
Mathematicsmatrices-and-determinants2021easy
Let A = \left[ {\matrix{
1 & 2 \cr
{ - 1} & 4 \cr
} } \right]. If A−1 = αI + βA, α, β∈ R, I is a 2 × 2 identity matrix then 4(α−β) is equal to :
Mathematicsmatrices-and-determinants2021medium
Let \theta \in \left( {0,{\pi \over 2}} \right). If the system of linear equations
(1+cos2θ)x+sin2θy+4sin3θz=0cos2θx+(1+sin2θ)y+4sin3θz=0cos2θx+sin2θy+(1+4sin3θ)z=0
has a non-trivial solution, then the value of θ is :
Mathematicsmatrices-and-determinants2021medium
If A = \left( {\matrix{
{{1 \over {\sqrt 5 }}} & {{2 \over {\sqrt 5 }}} \cr
{{{ - 2} \over {\sqrt 5 }}} & {{1 \over {\sqrt 5 }}} \cr
} } \right), B = \left( {\matrix{
1 & 0 \cr
i & 1 \cr
} } \right), i=−1, and Q = ATBA, then the inverse of the matrix A Q2021 AT is equal to :
Mathematicsmatrices-and-determinants2021medium
Let A = \left( {\matrix{
1 & 0 & 0 \cr
0 & 1 & 1 \cr
1 & 0 & 0 \cr
} } \right). Then A2025 − A2020 is equal to :
Mathematicsmatrices-and-determinants2021medium
If the matrix A = \left( {\matrix{
0 & 2 \cr
K & { - 1} \cr
} } \right) satisfies A(A3+3I)=2I, then the value of K is :
Mathematicsmatrices-and-determinants2021medium
Let A = \left( {\matrix{
{[x + 1]} & {[x + 2]} & {[x + 3]} \cr
{[x]} & {[x + 3]} & {[x + 3]} \cr
{[x]} & {[x + 2]} & {[x + 4]} \cr
} } \right), where [t] denotes the greatest integer less than or equal to t. If det(A) = 192, then the set of values of x is the interval :
Mathematicsmatrices-and-determinants2021medium
Let A(a, 0), B(b, 2b + 1) and C(0, b), b = 0, |b| = 1, be points such that the area of triangle ABC is 1 sq. unit, then the sum of all possible values of a is :
Mathematicsmatrices-and-determinants2021medium
Let [λ] be the greatest integer less than or equal to λ. The set of all values of λ for which the system of linear equations
x + y + z = 4,
3x + 2y + 5z = 3,
9x + 4y + (28 + [λ])z = [λ] has a solution is :
Mathematicsmatrices-and-determinants2021medium
If the following system of linear equations
2x + y + z = 5
x − y + z = 3
x + y + az = b
has no solution, then :
Mathematicsmatrices-and-determinants2021medium
If {a_r} = \cos {{2r\pi } \over 9} + i\sin {{2r\pi } \over 9}, r = 1, 2, 3, ....., i = −1, then
the determinant \left| {\matrix{
{{a_1}} & {{a_2}} & {{a_3}} \cr
{{a_4}} & {{a_5}} & {{a_6}} \cr
{{a_7}} & {{a_8}} & {{a_9}} \cr
} } \right| is equal to :
Mathematicsmatrices-and-determinants2021medium
If α + β + γ = 2π, then the system of equations
x + (cos γ)y + (cos β)z = 0
(cos γ)x + y + (cos α)z = 0
(cos β)x + (cos α)y + z = 0
has :
Mathematicsmatrices-and-determinants2021medium
Consider the system of linear equations
−x + y + 2z = 0
3x − ay + 5z = 1
2x − 2y − az = 7
Let S1 be the set of all a∈R for which the system is inconsistent and S2 be the set of all a∈R for which the system has infinitely many solutions. If n(S1) and n(S2) denote the number of elements in S1 and S2 respectively, then
Mathematicsprobability2021medium
An ordinary dice is rolled for a certain number of times. If the probability of getting an odd
number 2 times is equal to the probability of getting an even number 3 times, then the
probability of getting an odd number for odd number of times is :
Mathematicsprobability2021medium
The probability that two randomly selected subsets of the set {1, 2, 3, 4, 5} have exactly two elements in their intersection, is :
Mathematicsprobability2021easy
When a missile is fired from a ship, the probability that it is intercepted is {1 \over 3} and the probability that the missile hits the target, given that it is not intercepted, is {3 \over 4}. If three missiles are fired independently from the ship, then the probability that all three hit the target, is :
Mathematicsprobability2021medium
The coefficients a, b and c of the quadratic equation, ax2 + bx + c = 0 are obtained by throwing a dice three times. The probability that this equation has equal roots is :
Mathematicsprobability2021hard
Let A be a set of all 4-digit natural numbers whose exactly one digit is 7. Then the probability that a randomly chosen element of A leaves remainder 2 when divided by 5 is :
Mathematicsprobability2021medium
In a group of 400 people, 160 are smokers and non-vegetarian; 100 are smokers and vegetarian and the remaining 140 are non-smokers and vegetarian. Their chances of getting a particular chest disorder are 35%, 20% and 10% respectively. A person is chosen from the group at random and is found to be suffering from the chest disorder. The probability that the selected person is a smoker and non-vegetarian is :
Mathematicsprobability2021medium
A fair coin is tossed a fixed number of times. If the probability of getting 7 heads is equal to probability of getting 9 heads, then the probability of getting 2 heads is :