Find the least number which must be added to the number $59000$ to make it a perfect square. Also find the square root of the perfect square number so obtained.

If C.P. of an article is $₹500$ and S.P. is $₹600$, then his profit $\%$ is

Find the values of the letters in the following and give reasons for the steps involved:

$$\begin{gathered} 4 B A \\ \underline{+ 2 A 2} \\ \underline{ A 2 9} \end{gathered}$$

If $P=${letters of the word HYDERABAD} and

$Q=${letters of the word ALLAHABAD}, find

$P\cup Q$

$P\cap Q$

Also verify that $n\left(P\cup Q\right)=n\left(P\right)+n\left(Q\right)-n\left(P\cap Q\right)$.