$A$ jar contains $10$ red marbles and $30$ green ones. How many red marbles must be added to the jar so that $60 \%$ of the marbles will be red?

In an election,a candidate who gets $84 \%$ of the votes is elected by a majority of $476$ votes. What is the total number of votes polled?

In my office,at least $50 \%$ of the people read an e-newspaper. Among those who read an e-newspaper,at most $25 \%$ read more than one e-paper. Only one of the following statements follows from the statements given below. Which one is it?

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 $2006$?

If a number is increased by $20 \%$ and then reduced by $20 \%$,what is the net change in the number?

The population of a town is $32000$. It increases $15\%$ annually. What will it be in $2$ years?