$$ (17)^{2} + 6 × (13)^{2}-212×6$$

$$\sqrt{x}÷ \sqrt{144} = 0.02, $$ then the value of x is 

Simplify : $$\sqrt{[(12.1)^2-(8.1)^2]÷[(0.25)^2+(0.25)(19.95)]} $$

1-[5-{2+(-5+6-2)2}] is equal to 

If $$ {3\sqrt{{1-a}\over{a}}}+9={19-3\sqrt{{a}\over{1-a}}}$$, then what is the value of a?

Direction: what should come in place at question mark(?).

45% of 224×?% of 120=8104.32

The smallest natural number, by which 3000 must be divided to make the quotient a perfect cube, is : 

By what least number should 4320 be multiplied so as to obtain a number which is perfect cube?