The population of Delhi two years ago was $55000$. It increased by $12 \%$ in the first year and decreased by $15 \%$ in the second year. What was the population of the town at the end of $2$ years?

In an examination,$37 \frac{1}{2} \%$ of the candidates were girls. If $75 \%$ of the boys and $62 \frac{1}{2} \%$ of the girls passed,and $342$ girls failed,find the number of boys who failed.

Aditya's salary is $125\%$ of Ram's salary. Sanjay's salary is $80\%$ of Ram's salary. If the total of all the three salaries is $Rs. 61000$,what is Sanjay's salary?

The percentage of metals in a mine of lead ore is $60 \%$. Now, the percentage of silver is $3/4 \%$ of the metals and the rest is lead. If the mass of ore extracted from this mine is $8000 \, kg$, what is the mass (in $kg$) of lead?

$A$ sum of $₹ 731$ is distributed among $A$,$B$,and $C$,such that $A$ receives $25\%$ more than $B$ and $B$ receives $25\%$ less than $C$. What is $C$'s share in the amount?

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: