In an election between two candidates,$10 \%$ of the voters did not cast their vote. $10 \%$ of the votes polled were found invalid. The successful candidate received $54 \%$ of the valid votes and won by a majority of $1620$ votes. The total number of voters enrolled on the voter's list was:

$A$ number is decreased by $10 \%$ and then increased by $10 \%$. The number so obtained is $10$ less than the original number. What was the original number?

If inflation increases at a rate of $8 \%$ p.a.,what will a $₹ 20$ article cost at the end of two years?

If $8 \%$ of the people eligible to vote are between $18$ and $21$ years of age,and in an election,$85 \%$ of those eligible to vote who were between $18$ and $21$ years of age actually voted,then the number of persons between $18$ and $21$ years of age who actually voted is what percent of the total people eligible to vote?

$A$ 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 entrance examination,Ritu scored $56\%$ marks,Smita scored $92\%$ marks,and Rina scored $634$ marks. The maximum marks of the examination are $875$. What are the average marks scored by all the three girls together?