$A$ person's salary has increased from $Rs. 7200$ to $Rs. 8100$. What is the percentage increase in his salary (in $\%$)?

$25 \%$ of $25 \% = ?$

Six-elevenths of a number is equal to $22 \%$ of a second number. The second number is equal to one-fourth of a third number. The value of the third number is $2400$. What is $45 \%$ of the first number?

When a number is divided by $12$,the quotient becomes $1/4$ of another number. By what percentage is the first number greater than the second number?

$A$ person who spends $66 \frac{2}{3} \%$ of his income is able to save $₹ 1200$ per month. His monthly expenses (in $₹$) are

Rajiv spends $20 \%$ of his salary on food,$15 \%$ on conveyance,$10 \%$ on education,and $35 \%$ on house rent. If he spends $Rs. 1950$ on education,how much does he spend on conveyance?