# Math Help - percentage?

1. ## percentage?

each year for the past 5 years the population of a certain country has increased at a steady rate of 2.7% per annum. the present population is 15.2 million

a) what was the population 1 year ago?

b) what was the population 5 years ago?

i dnt understand the q, has this got anything to do with compound interest field? ive slightly touched on the subject in skl, isit exponential? can i have working out please so i can understand...

2. Originally Posted by exclusiive
each year for the past 5 years the population of a certain country has increased at a steady rate of 2.7% per annum. the present population is 15.2 million

a) what was the population 1 year ago?
$15.2 ~\text{million} - .027 \times 15.2 ~\text{million}$

Originally Posted by exclusiive

b) what was the population 5 years ago?

i dnt understand the q, has this got anything to do with compound interest field? ive slightly touched on the subject in skl, isit exponential? can i have working out please so i can understand...
Try $P = 15,200,000\times (97.3)^5$

3. i dnt think its working out...
i have the answers, but im trying to figure out the working....

a) 14,793,187
b) 13,271,941