If $$ {0.7\over 1-6c}=-0.2$$ then what is the value of c.

The largest number of five digits, which is a perfect square is 

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? 

The Value of $$ {\sqrt{6-\sqrt{17-2\sqrt{72}}}}$$ is closest to:

Find the value of given equations

$$\left({216\over1} \right) ^{-{2\over3}}÷\left({27\over1} \right) ^{-{4\over3}}=? $$

The value of $$ {\sqrt{0.6912}+{\sqrt{0.5292}}\over {\sqrt{0.6912}-{\sqrt{0.5292}}}}$$ is:

Find the value of $$ {5^{1\over2}-[3^{1\over4}+6-4÷2]}$$

Simplify : $$ {5\over3}×{7\over51}\ of \ {17\over5}-{1\over3}\over {2\over9}×{5\over7}\ of \ {28\over5}-{2\over3}  $$