Question

the population of a village increases by 10% every year. It's population at the end of 2015 was 7986. What was its population at the beginning of 2013

Answer 1

For this formula will be
%Increase=Increase/base value×100
but we don't have the base value
so percent increase in population=10%
Let the population of 2013 be x
%Increase=Increase/base value×100
The increase in population in 2015 is 7986
so, 10%= 7986/x×100
transfer x with 10percent
so,we will have
10%=7986×100
10x%=798600
so x is equal to
x=798600/10
so the answer will be equal to
79860
Please let me know if the ans was correct or not.

Answer 2

Let the population of the village at the beginning of 2013 be x
•population at the end of 2013
= x+(10/100)x
= (11/10)x

•population at the end of 2014
= (11/10)x+(11/100)x
= (121/100)x

•population at the end of 2015
7986 = (121/100)x+(121/1000)x
7986 = (1210+121/1000)x
x = 7986/1331
x = 6

hence the population at the beginning of 2013 was 6.


hope this helped............