$a \%$ of $b + b \%$ of $a =$

If $₹ 2800$ is $\frac{2}{7}$ percent of the value of a house,the worth of the house (in $₹$) is

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?

Pradeep invested $20\%$ more than Mohit. Mohit invested $10\%$ less than Raghu. If the total sum of their investment is $₹ 17,880$,how much amount did Raghu invest?

What per cent of a day is $3$ hours?

To attract more visitors,the zoo authority announces a $20 \%$ discount on every ticket,which costs $25 \ p$. For this reason,the sale of tickets increases by $28 \%$. Find the percentage of increase in the number of visitors.