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?

Two litres of water evaporate from $10$ litres of a solution containing $10 \%$ salt. The percentage of salt in the remaining solution is

The difference of two numbers is $20 \%$ of the larger number. If the smaller number is $20$,then the larger number is:

Two numbers are $30 \%$ and $40 \%$ more than the third number respectively. The first number is $x \%$ of the second. Then $x = ?$

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

In an examination,the percentage of students qualified to the number of students appeared from school $A$ is $70 \%$. In school $B$,the number of students appeared is $20 \%$ more than the students appeared from school $A$ and the number of students qualified from school $B$ is $50 \%$ more than the students qualified from school $A$. What is the percentage of students qualified to the number of students appeared from school $B$?