Question

the population of a town increases 10% anually.if its present population is 220000. what was it a year ago

Answer 1

let the population a year ago=p
population now=22000
thus p(1+10/100)=22000
p(1+0.1)=22000
p×1.1=22000
p=22000/1.1=20,000
it's population a year ago was 20,000

Answer 2

$110 = 220000 \\ 1 = \frac{220000}{110} \\ 1 = 2000 \\ 100 = 200000$