The price of cooking oil has increased by $25 \%$. The percentage of reduction that a family should effect in the use of cooking oil,so as not to increase the expenditure on this account,is (in $\%$)

Number of appeared candidates from State $Q$ increased by $100 \%$ from $2006$ to $2007$. If the total number of qualified candidates from State $Q$ in $2006$ and $2007$ together is $408$,what is the number of appeared candidates from State $Q$ in $2006$?

$A$ businessman imported laptops worth $Rs$ $210,000$,mobile phones worth $Rs$ $100,000$,and television sets worth $Rs$ $150,000$. He had to pay $10\%$ duty on laptops,$8\%$ on phones,and $5\%$ on television sets. How much total duty (in Rupees) did he have to pay on all items as per the above details?

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:

If $A = x \%$ of $y$ and $B = y \%$ of $x$,then which of the following is true?

$A$ number is increased by $84$,it becomes $107 \%$ of itself. What is the number?