If all sides of a hexagon are increased by $7 \%$,find the percentage increase in its area. (in $\%$)

The population of a city increases at the rate of $5 \%$ per annum. If the present population of the city is $3,70,440$,its population $3$ years ago was:

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

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?

If $35 \%$ of a number is $12$ less than $50 \%$ of that number,then the number is:

The cost price of goods of a bankrupt is $Rs. 25500$. If the goods had been realised at their full value,his creditors would have received $85$ paise in the rupee. But $2/5$ of the goods were sold at $17\%$ below their cost price and the remainder at $22\%$ below their cost price. How many paise in a rupee was received by the creditors?