Question

the population of a town increased to 8000 in 2 years at the rate of 6% per annum find the population in 2008

Answer 1

Final Population = Initial Popular (1 + growth rate)^no of years

Let the population in 2008 be x

8000= x(1 + 0.06)^2

1.1236x = 8000

x = 8000 ÷ 1.11236

x = 7120

Answer: 2 years ago (year 2008), the population was 7120.

Answer 2

here is your answer OK

This can be blissfully solved by a single formula.

Final population after increment and decrement respectively=
(actual population) *(increament rate) *(decrement rate)

=1,00,000*(110/100)^2 *(90/100)^2
=1,00,000*(1. 21)*(0.81)
=98010