Mr. Giridhar spends $50 \%$ of his monthly income on household items. Out of the remaining,he spends $50 \%$ on transport,$25 \%$ on entertainment,and $10 \%$ on sports. If the remaining amount of $RS. 900$ is saved,what is Mr. Giridhar's monthly income?

The sum of two numbers is $\frac{28}{25}$ of the first number. The second number is what percent of the first (in $\%$)?

$A$ 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?

In an examination,$70 \%$ of the candidates passed in English,$80 \%$ passed in Mathematics,and $10 \%$ failed in both subjects. If $144$ candidates passed in both,the total number of candidates was:

In an election between two candidates,one got $55 \%$ of the total valid votes,and $20 \%$ of the total votes were invalid. If the total number of votes polled was $7500$,what was the number of valid votes that the other candidate received?

If the height of a triangle is decreased by $40 \%$ and its base is increased by $30 \%$,what will be the effect on the area?