The rationalising factor of sqrt(5) + sqrt(3) is:

The expression is $\sqrt{5} + \sqrt{3}$.

For an expression of the form $\sqrt{a} + \sqrt{b}$, its rationalizing factor is $\sqrt{a} - \sqrt{b}$.
Therefore, the rationalizing factor of $\sqrt{5} + \sqrt{3}$ is $\sqrt{5} - \sqrt{3}$.

The correct option is A.

2. In a cricket match two batsmen together scored 181 runs. The linear equation form for the statement is:

Let $x$ be the runs scored by the first batsman.
Let $y$ be the runs scored by the second batsman.

"Two batsmen together scored 181 runs" means the sum of their runs is 181.
So, $x + y = 181$.

The correct option is C.

3. In a parallelogram, if the adjacent angles are in the ratio 2:3, then the measure of these adjacent angles are:

Adjacent angles in a parallelogram are supplementary, meaning their sum is $180^\circ$.

Let the adjacent angles be $2k$ and $3k$.

First angle: $2k = 2 \times 36^\circ = 72^\circ$
Second angle: $3k = 3 \times 36^\circ = 108^\circ$

The correct option is B.

4. If the radius of a sphere is $2r$, then its volume will be:

The volume $V$ of a sphere with radius $R$ is given by:

Given radius $R = 2r$.

The correct option is D.