If an electricity bill is paid before the due date,one gets a reduction of $4 \%$ on the amount of the bill. By paying the bill before the due date,a person got a reduction of $₹ 13$. The amount of his electricity bill was:

The price of cooking oil has increased by $15 \%$. The percentage of reduction that a family should effect in the use of cooking oil so as not to increase the expenditure on this account is:

Pooja invests $13 \%$ of her monthly salary,i.e.,$Rs. 8554$ in Mediclaim Policies. Later she invests $23 \%$ of her monthly salary on Child Education Policies,she also invests another $8 \%$ of her monthly salary on Mutual Funds. What is the total annual amount invested by Pooja?

The population of a city increases at the rate of $5 \%$ per annum. If the present population of the city is $3,70,440$,its population $3$ years ago was:

In Jamshedpur,only two newspapers,Dainik Jagran and Prabhat Khabar,are published. It is known that $25 \%$ of the city population reads Dainik Jagran and $20 \%$ reads Prabhat Khabar,while $8 \%$ reads both the newspapers. It is also known that $30 \%$ of those who read Dainik Jagran but not Prabhat Khabar look into advertisements,$40 \%$ of those who read Prabhat Khabar but not Dainik Jagran look into advertisements,and $50 \%$ of those who read both the newspapers look into advertisements. What is the percentage of the population who read an advertisement?

Express $\frac{7}{8}$ as a percentage.