On simplification of   $$ {(2.664)^2-(2.356)^2\over0.288}$$

5-[4-{3-(3-3-6)}] is equal to:

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

Find the value of   $$ {(0.75)^3\over1-.75}+[0.75+(0.75)^2+1]$$

Simplify the following equation
$$ {\sqrt{(1-sin^{2}θ) ÷{(1-cos^{2}θ)}}}$$

The sum of the squares of 2 number is 146 and the square root of one of them is 5. The cube of the other number is 

2x + 4y – 8xy -1 =?

In a group of 15 women, 7 have nose studs, 8 have ear rings and 3 have neither. How many of these have both nose studs and ear rings?