Four statements are given followed by four conclusions. Mark which of the given conclusion(s) definitely follows from the given statements even if they seem to be at variance from commonly known facts.
Statements:
(A) Some cats bark.
(B) Those who bark do not sleep.
(C) All elephants sleep.
(D) No cat is elephant.
Conclusions:
I) Some cats do not sleep.
II) Some elephants bark.
III) The cats that bark are elephants.
IV) Elephants that do not bark are cats.

The sum of squares of all the roots of the equation:
​$$\left(x + \frac{1}{x}\right)^2 - 4 = \frac{3}{2} \left(x - \frac{1}{x}\right), x \neq 0$$ is:

One of the factors of 6x² – 24xy + 17x + 24y² – 34y + 5 is:

The cost of 2 pens and 5 pencils is ₹ 57. If the cost of a pen is increased by ₹ 1.50 and that of a pencil is decreased by ₹ 1, then the cost of 5 pens and 3 pencils is ₹ 109. What is the original cost of 3 pens and 4 pencils?

What is the remainder when the polynomial x¹⁰⁰ – 2x⁵¹ + 1 is divided by (x² – 1) ?

If x + $$\frac 1x$$​= –1, then compute: $$x^4 + \frac{1}{x^4} + 2x^2 + \frac{2}{x^2}$$​​

Let x be the greatest number which, when dividing 31, 61 and 91, leaves the same remainder. The LCM of x and 48 is:

The value of $$\frac{x}{x-y}+\frac{y}{x+y}+\frac{2xy}{y^{2}-x^{2}}$$​ is