if $$x=\sqrt {64}+\sqrt {121}-\sqrt {169}$$, the find the value of x²

If $$ {(x^{3})^{3} × x^{5}\over{x^{4}}}=x^{n}$$ then find the value of n.

A room in a house measures 5 m in height and its length is 3 times its breadth. The cost of whitewashing its four walls at Rs. 2.50 per sq m is Rs. 200. What is the cost of carpeting the floor at Rs. 5 per sq m? 

If $$\sqrt { 3}=1.732$$ then the find the value of $${9+2{ \sqrt { 3}}}\over  \sqrt { 3}$$  

What is the smallest number to be added to 2203, so that we get the sum of a perfect square number?

Simplify the following

  $${\sqrt { 10+{\sqrt { 25+ {\sqrt { 108 +\sqrt { 154+ \sqrt { 225} \ } \ } \ }} \ } } \ }\over \sqrt { 16+ 19.25×4^2} $$

Which of the following quadratic equations has real roots?

The ratio of the square of a number and the inverse of its cube is 243/16807. what is the number?