Question

The population of a town is increasing at the rate of 5% per annum. What will be the population of the town on this basis after two years, if the present population is 16000?​

Answer 1

Answer:

Its a problem of compound interest.

Present population: 16000

Rate: +5

Time: 2 year

Note: compound interest works on interests.

method 1: apply formulae

Population after 2 years= 16000(1+(5/100))^2

= 16000×105×105/100×100

= 8×105×21

= 840×21

=16800+840= 17640

method 2:

First year s.i.on 16000= 800

2nd year s.i. on 16000=800

Interest on 1st year s.i.= 40

Next interest = 1640

Population after 2 years= 16000+ 1640= 17640