$A$ number is increased by $20 \%$ and then decreased by $20 \%$. What is the final percentage change in the number?

In an election between two candidates,one got $52 \%$ of the total valid votes. $25 \%$ of the total votes were invalid. The total number of votes were $8400$. How many valid votes did the other person get?

In Mumbai,$60 \%$ of the registered voters are $BJP$-supporters and the rest are Congress-supporters. In a mayoral race,if $75 \%$ of the registered voters who are $BJP$-supporters and $20 \%$ of the registered voters who are Congress-supporters are expected to vote for candidate $X$,what percent of the registered voters are expected to vote for candidate $X$?

Find a single equivalent increase,if a number is successively increased by $10 \%$,$20 \%$,and $25 \%$. (in $\%$)

Fresh fruits contain $68 \%$ water and dry fruits contain $20 \%$ water. How much dry fruit can be obtained from $100 \,kg$ of fresh fruits?

Christy donated $10 \%$ of his income to an orphanage and deposited $20 \%$ of the remainder in his bank. If he has now $Rs$ $7200$ left,what is his income?