$A$'s salary is $40 \%$ of $B$'s salary,which is $25 \%$ of $C$'s salary. What percentage of $C$'s salary is $A$'s salary?

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

Shruti decided to donate $12 \%$ of her salary to an orphanage. On the day of donation,she changed her mind and donated $Rs. 3150$,which was $75 \%$ of what she had decided earlier. How much is Shruti's salary?

The production of a company has ups and downs every year. The production increases for two consecutive years consistently by $15 \%$ and in the third year it decreases by $10 \%$. Again in the next two years it increases by $15 \%$ each year and decreases by $10 \%$ in the third year. If we start counting from the year $1998$,approximately what will be the effect on the production of the company in $2002$?

$A$ number,when $35$ is subtracted from it,reduces to its $80$ percent. What is four-fifths of that number?

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?