The population of a town increased by 10% per year in 2009, 2010, and 2011. If the population of the town at the beginning of 2009 was 40,000, what was it at the end of 2011?

Assuming that the population follows an exponential function, the it will take the form:

y=a (bˣ)

where:

a=initial value

b=growth factor

x=time

thus plugging our values in the equation we get:

y=40000 (1.1ˣ)

thus the population in 2011 when t=3 will be:

y=40000 (1.1³)

y=53240