A town had 10,000 residents in 2000. Its population declines at a rate of 10% per annum. What will be its total population in 2005?

The population of the town decreases by 10% every year.
Thus, it has a new population every year. So the population for the next year is calculated on the current year population.
For the decrease, we have the formula A = P(1 - R/100)ⁿ

Therefore,
the population at the end of 5 years
= 10000(1 - 10/100)⁵
= 10000(1 - 0.1)⁵
= 10000 x 0.9⁵
= 5904.9