Question

Rationalising factor of $2\sqrt{3}-\sqrt{5}$ is :

• A. $\sqrt{5}-2\sqrt{3}$
• B. $\sqrt{3}+2\sqrt{5}$
• C. $\sqrt{12}+\sqrt{5}$
• D. None of these

Answer 1

The correct option is C $\sqrt{12}+\sqrt{5}$

Rationalising factor is a term with which a term is multiplied or divided to make the whole term rational.
The rationalizing factor of $\sqrt{a}-\sqrt{b}$ is $\sqrt{a}+\sqrt{b}$

Given irriational number is $2\sqrt{3}-\sqrt{5}$

So,the rationalisation factor will be $2\sqrt{3}+\sqrt{5}$

$=\sqrt{2^2\times 3}+\sqrt{5}$

$=\sqrt{12}+\sqrt{5}$.

So, correct answer is option C.