The length of a rectangle is increased by $30 \%$ and the breadth by $20 \%$. Then the perimeter of the rectangle will increase by what percent?

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.

Starting with $8000$ workers,the company increases the number of workers by $5 \%$,$10 \%$,and $20 \%$ at the end of the first,second,and third year,respectively. The number of workers in the fourth year is:

If $x$ $\%$ of $y$ is $100$ and $y$ $\%$ of $z$ is $200,$ then find a relation between $x$ and $z$.

The price of an article is Rs. $100$. Its price is increased by $10 \%$,and then again its price is increased by $10 \%$. What is the total increase in the price?

Two numbers $A$ and $B$ are such that the sum of $6\%$ of $A$ and $4\%$ of $B$ is two-thirds of the sum of $6\%$ of $A$ and $8\%$ of $B$. Find the ratio of $A:B$.