$67 \%$ of $801 - 231.17 = ? - 23 \%$ of $789$

How much pure alcohol has to be added to $400 \text{ ml}$ of a solution containing $15 \%$ alcohol to change the concentration of alcohol in the mixture to $32 \%$?

Due to an increase of $30 \%$ in the price of eggs,$3$ eggs less are available for $₹ 7.80$. The present rate of eggs per dozen is:

$40 \%$ are the passing marks. $A$ student gets $250$ marks yet fails by $38$ marks. What is the maximum marks?

In a recent opinion poll held during April,$60 \%$ of the respondents favoured India Against Corruption $(IAC)$ while the rest favoured Indian political parties $(IPP).$ It was found in May polls that $10 \%$ of $IAC$ supporters switched their preference to $IPP,$ while the same percentage of $IPP$'s supporters also switched their preference to $IAC.$ What percentage of the electorate should now switch their preference from $IAC$ to $IPP$ so that they are at par?

The total population of a village is $5000$. The number of males and females increases by $10\%$ and $15\%$ respectively,and consequently,the population of the village becomes $5600$. What was the number of males in the village?