Find the value

$\sqrt[5]{(243)^{-3}}$

Which of the following is irrational?

Fill in the blanks so as to make each of the following statements true (Final answer only)

$\sqrt{2} \cdot \sqrt{3} \cdot \sqrt{6}=\ldots \ldots .$

Insert a rational number and an irrational number between the following:

$6.375289$ and $6.375738$

If $a=2+\sqrt{3},$ then find the value of $a-\frac{1}{a}$

For each question, select the proper option from four options given, to make the statement true : (Final answer only)

$.............$ is a rational number between $7$ and $8 .$