$860\%$ of $50 + 50\%$ of $860 = ?$

If the length of a rectangle is increased by $20\%$ and its breadth is decreased by $10\%$,what will be the impact on its area?

If $37 \frac{1}{2} \%$ of a number is $45,$ then $87 \frac{1}{2} \%$ of the number will be:

In a class of $50$ students and $5$ teachers,each student received sweets equal to $12 \%$ of the total number of students,and each teacher received sweets equal to $20 \%$ of the total number of students. How many sweets were there in total?

If the income of $R$ is $30 \%$ more than the income of $Q$ and the income of $Q$ is $20 \%$ more than the income of $P$,then the income of $R$ is how much percent more than the income of $P$ (in $\%$)?

Two numbers are respectively $20 \%$ and $10 \%$ more than a third number. How much per cent is the first number more than the second?