Question

the population of a town increase at the rate of 10% during 1st year and decrease at the rate of 10% during the second year if it has 29700 in habitants at present find the number of inhabitants 2 years ago

Answer 1

x = the number of inhabitans 2 years ago
x + 0.1x = 1.1x = the number of inhabitans 1 years ago
1.1x * (1 - 0.1) = the number of inhabitans now

1.1 * 0.9 x = 29700
0.99x = 29700 
x = 29700 / 0.99 = 30000

Answer: Two years ago it was 30,000 inhabitants.

Answer 2

Answer:

Let the population two years ago be = x

According to the question, 38400=1.20×0.80×x

x=

0.96

38400

=40,000

Hence, population two years ago was 40,00