The income of a company increases $20 \%$ per annum. If its income is $Rs$ $42664000$ in the year $1999$,what was its income in the year $1997$?

The average marks obtained in a class of $50$ students is $70 \%$. The average of the first $25$ students is $60 \%$ and that of the next $24$ students is $80 \%$. What is the percentage of marks obtained by the last student?

$4598$ is $95 \%$ of what number?

$A$ fruit seller had some apples. He sells $40 \%$ of the apples and still has $420$ apples. Originally,how many apples did he have?

In a company,there are $75\%$ skilled workers and the remaining are unskilled. $80\%$ of skilled workers and $20\%$ of unskilled workers are permanent. If the number of temporary workers is $126$,what is the total number of workers?

If $35 \%$ of $A$'s income is equal to $25 \%$ of $B$'s income,then the ratio of $A$'s income to $B$'s income is