If x = 222, y = 223 and z = 224, then find the value of x³+y³+z³-3xyz

Direction: What approximate value will come in place of the question mark (?) in the following question? (You are not expected to calculate the exact value)

?³ + 115.86 – 24.93 × 1.90 = 190.97

The value of $$5-{8+2\sqrt{15} \over4}-{{1}\over8+2\sqrt{15}}$$ is equal to:

If a³ – b³ – c³ – 3abc = 0, then 

$$\left({?-0.5\over 0.2} \right)={120\over 2}$$

Direction: What approximate value will come in place of the question mark (?) in the following question? (You are not expected to calculate the exact value)

(16.05)² + (8.96)² - 7.03 × 3.98 =? + 197.99

If p – 2q = 4, then the value of p³ – 8q³ – 24pq – 64 is :

$$ if \ {1\over x}+x=4,$$ then find $${1\over x^2}+x^2$$