The value of $\sqrt{8} + \sqrt{18}$

1. $\sqrt{26}$
2. $2(\sqrt{2} + \sqrt{3})$
3. $5\sqrt{2}$
4. $6\sqrt{2}$

The number $(2 - \sqrt{3})^2$ is

1. a natural number
2. an integer
3. a rational number
4. an irrational number

If x, y are both positive rational numbers, then $(\sqrt{x} + \sqrt{y})(\sqrt{x} - \sqrt{y})$ is

1. a rational number
2. an irrational number
3. neither rational nor irrational number
4. both rational as well as irrational number

After rationalising the denominator of $\dfrac{7}{3\sqrt3 - 2\sqrt{2}}$ , we get the denominator as

1. 13
2. 19
3. 5
4. 35