$A$ person scores $45 \%$ of the total marks in the exam and still fails by $40$ marks. The passing percentage of the exam is $55 \%$. What is the maximum marks of the exam?

Sunil decided to donate $5 \%$ of his salary. On the day of donation,he changed his mind and donated $₹ 1687.50$,which was $75 \%$ of what he had decided earlier. How much is Sunil's salary?

In expressing a length $81.472 \, km$ as nearly as possible with three significant digits,find the percentage error?

An index of $12$ shares contains,among others,the shares of Vision Power,Vision Infra,and Vision Communication with weightage of $7\%$,$13\%$,and $15\%$ respectively. What is the increase in the prices of other shares,if these three rise by $9\%$,$10\%$,and $4\%$ respectively,while the index rises by $6\%$?

Ramesh loses $20 \%$ of his pocket money. After spending $25 \%$ of the remainder,he has $₹ 480$ left. What was his pocket money?

What is $15$ percent of Rs. $34$?