In an examination,$35 \%$ of the students passed and $455$ failed. How many students appeared for the examination?

$A$ student secures $90\%$,$60\%$ and $54\%$ marks in test papers with $100$,$150$ and $200$ respectively as maximum marks. The percentage of his aggregate is:

In a test,a candidate secured $468$ marks out of maximum marks $A$. If the maximum marks $A$ were converted to $700$ marks,he would have secured $336$ marks. What were the maximum marks of the test?

If a number is increased by $20 \%$ and then reduced by $20 \%$,what is the net change in the number?

The average salary of male employees in a firm was $Rs$ $5200$ and that of females was $Rs$ $4200$. The mean salary of all the employees was $Rs$ $5000$. What is the percentage of female employees?

$A$ pharmaceutical company received $Rs. 3$ million in royalties on the first $Rs. 20$ million in sales of the generic equivalent of one of its products and then $Rs. 9$ million in royalties on the next $Rs. 108$ million in sales. By approximately what percent did the ratio of royalties to sales decrease from the first $Rs. 20$ million in sales to the next $Rs. 108$ million in sales?