In expressing a length $81.472 \, km$ as nearly as possible with three significant digits,find the percentage error?

$1$ quintal $25$ $kg$ is what percent of $1$ metric tonne?

In an examination,$35 \%$ of the students passed and $455$ failed. How many students appeared for the examination?

What percent of a day is $3$ hours?

$A$ pharmaceutical company received $Rs. 3$ million in royalties on the first $Rs. 20$ million in sales of the generic equivalent of one of its products and then $Rs. 9$ million in royalties on the next $Rs. 108$ million in sales. By approximately what percent did the ratio of royalties to sales decrease from the first $Rs. 20$ million in sales to the next $Rs. 108$ million in sales?

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?