Question

In 2000, there were 750 cell phone subscribers in a small town. The number of subscribers increased by 80% per year after 2000. How many cell phone subscribers were in 2010? Round off the answer to the nearest whole number.

Answer 1

This is an exponential growth. We would apply the exponential growth formula which is expressed as

y = a(1 + r)^t

Where

a represents the imitial number of subscribers

r represents the growth rate

t represents the number of years

y represents the number of subscribers after t years

From the information given,

a = 750

r = 80/100 = 0.8

t = 9 (number of years between 2000 and 2010)

Thus,

y = 750(1 + 0.8)^9

y = 750(1.8)^9

y = 148769.48

Rounding to the nearest whole number, the number of cell phone subscribers in 2010 is

148769