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Q1:

2025: Actual Paper

Matrices & Determinants

Medium

Let bb and cc be two real numbers such that the numbers 3,b,c3, b, c are in a geometric progression. For the matrix A=[1113bc9b2c2]A = \begin{bmatrix} 1 & 1 & 1 \\ 3 & b & c \\ 9 & b^2 & c^2 \end{bmatrix}, if det⁡[A]=162\det[A] = 162, then the value of cc is

Answer options
Option 4
Correct Answer
Explanation for 2025: Actual Paper QA question 1

Q2:

2025: Actual Paper

Matrices & Determinants

Medium

Let A=[x101]A = \begin{bmatrix} x & 1 \\ 0 & 1 \end{bmatrix} where xx is a real number, and B=[223+201]B = \begin{bmatrix} 2\sqrt{2} & 3 + \sqrt{2} \\ 0 & 1 \end{bmatrix}. If A3=BA^3 = B, then xx is equal to

Answer options
Option 2
Correct Answer
Explanation for 2025: Actual Paper QA question 2

Q3:

2025: Sample Paper

Matrices & Determinants

Hard

Let A=[aij]A = [a_{ij}] be a 3 × 3 matrix such that aij=i+ja_{ij} = i + j, for all i,ji, j. If A3+kA2+lA+mI=0A^3 + kA^2 + lA + mI = 0, then k+l+mk + l + m is equal to

Answer options
Option 3
Correct Answer
Explanation for 2025: Sample Paper QA question 3