The value of x in the given equation
$$ {23 ^2 + \sqrt{x}=625}$$

If  $$\sqrt{2}=1.414$$, the value of $${ \sqrt{2}-1\over\sqrt{2}+1}$$  is nearest to 

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

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

The smallest number that must be subtracted from 1000 to make the resulting number 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? 

Find the value of given equations

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

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