Originally Posted by

**bhuang** The question is posted below and I have attached my solution, which is close to the values in the answer section, but only when I round it.

Each year for the past five years the population of a certain counry has increased at a steady rate of 2.7% per annum. The present population is 15.2 million.

a) What was the population one year ago?

b) What was the population five years ago?

My solution:

U6 (6th term)=15.2 million

common ratio=1.027

U1 = first term

U6 = U1(1.027)^5

15.2 million = U1(1.027)^5

Therefore, b) U1=13.3 million

and a) U5 (fifth term) = U1(1.027)^4

= 13.3(1.027)^4

= 14.8 million

Now, the answer in the book is: a) 14 793 187 b) 13 271 941

even if I don't round my values, they still aren't the same as the book's. Did I do this question right?