The minimum value of $ax + by$, where $xy = c^2$ and a, b, c are positive, is :

If $K \equiv 5 \pmod{11}$, then all the possible non-negative values of K are :

If a square matrix B satisfies $B^2 = I - B$ and $B^n = 5I - 8B$, then the value of n is :

Let A be a square matrix. Then,

(A) $A + A^T$ is a symmetric matrix

(B) $A - A^T$ is a skew-symmetric matrix

(C) $AA^T$ is a skew-symmetric matrix

(D) $A^T A$ is a symmetric matrix

Choose the correct answer from the options given below :

For a 3 $\times$ 3 matrix A = [a$_{ij}$], whose element a$_{ij}$ is given by $a_{ij} = \sqrt{i^2 + 3j}$ then what is element a$_{31}$?

A point $P(3a, -2b)$ lies in region $4x + 7y \leq (-3)$ which of the following options is true ?

The solution set of the inequation $\frac{7+5x}{4} \geq \frac{x}{3} - 10$, $x \in \mathbb{R}$ is :