If a³ – b³ – c³ – 3abc = 0, then 

What is the value of $${{0.6}÷{0.6}×{0.6}+{0.5}×{0.5}÷{0.5}\over{0.6}×{0.5}+{0.3}}$$ ?

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

If  $${{(17)^3-(7)^3}\over (17^2+7^2+k)}=10 $$ , then what is the value of k?

Simplify the following expression.
12 + 2.5 + (1.5 of 4) - 2.6

$$ {40 \%}\ of( {20\over 4}×?)=48$$

If 5x + 5 > 2 + 2x and 5x + 3 ≤ 4x + 5; then x can take which of the following values?

(0.85 % of 405 ) + (2.25 % of 550 )=?