If $75 \%$ of a number is added to $75$,the result is the number itself. The number is:

On decreasing the price of a colour $TV$ by $30 \%$,its sale is increased by $20 \%$. The effect on the revenue is:

$A$ man spends $75 \%$ of his income. His income is increased by $20 \%$ and he increases his expenditure by $10 \%$. By what percentage does his saving increase (in $\%$)?

$405$ toffees were distributed equally among children in such a way that the number of toffees received by each child is $20 \%$ of the total number of children. How many toffees did each child get?

In an examination,it is required to get $256$ of the total maximum aggregate marks to pass. $A$ student gets $192$ marks and is declared failed. The difference between the marks obtained by the student and the marks required to pass is $10 \%$. What are the maximum aggregate marks a student can get?

Christy donated $10 \%$ of his income to an orphanage and deposited $20 \%$ of the remainder in his bank. If he has now $Rs$ $7200$ left,what is his income?