What is $15$ percent of Rs. $34$?

Two jars contain equal quantities of $40 \%$ alcohol. Swati changed the concentration of the first jar to $50 \%$ by adding extra quantity of pure alcohol. Sonali changed the concentration of the second jar to $50 \%$ by replacing a certain quantity of the solution with pure alcohol. By what percentage is the quantity of alcohol added by Swati more than that replaced by Sonali?

$? \times 15 = 37.5 \%$ of $220$

Two numbers are less than a third number by $30 \%$ and $37 \%$ respectively. How much per cent is the second number less than the first (in $\%$)?

The population of a town $2$ years ago was $62500$. Due to migration to big cities,it decreases every year at the rate of $4\%$. The present population of the town is:

The difference between two numbers is $1600$. If $7.5\%$ of one number is equal to $12.5\%$ of the other number,find the two numbers.