If $20 \%$ of $a = b$,then $b \%$ of $20$ is the same as: (in $\%$ of $a$)

The present population of a town is $26010$. It increases annually at the rate of $2\%$. What was the population of the town two years ago?

The population of a city is $20000$. It increased by $20\%$ during the first year and $30\%$ during the second year. The population after two years will be:

Suman's project report on 'Development with dignity',consists of $25$ pages,each with $60$ lines and $75$ characters per line. If the number of lines is reduced to $55$ but the number of characters per line is increased to $90$,what is the percentage change in the number of pages? (Assume the number of pages to be a whole number.)

If $A$'s salary is $50 \%$ more than that of $B$,then $B$'s salary is less than $A$'s by

$A$ speaks truth in $80 \%$ of the cases and $B$ in $90 \%$ of the cases. Find the percentage when they contradict each other in describing the same facts. (in $\%$)