Two-thirds of three-fourths of one-fifth of a number is $15$. What is $30$ per cent of that number?

Aditya's salary was increased by $40 \%$ and then decreased by $25 \%$. Find the net effect on Aditya's salary.

If $A$ is $150 \%$ of $B$,then $B$ is what percent of $A+B$?

Sweta invested $Rs. 10,000$ in a scheme exactly three years ago. The value of the investment increased by $10\%$ during the first year,increased by $5\%$ during the second year,and decreased by $10\%$ during the third year. What is the value of the investment today?

If $60 \%$ of the students in a school are boys and the number of girls is $812$,how many boys are there in the school?

$A$'s salary is $50 \%$ more than $B$'s. How much percent is $B$'s salary less than $A$'s?