Question

The Population of a town is 1,76,400. If it increases at the rate of 5% per annum, what will be its population 2 years? What was it 2 years ago?

Answer 1

population after 2 years = 176400×105/100×105/100

= 176400 × 21/20 ×21/20

= 176400 × 441/400

= 194481

population before 2 years


176400×100/105×100/105

= 176400 × 20/21 ×20/21

= 176400 × 400/441

= 160000

Answer 2

Answer:

The population after 2 years is 194481. The population after 2 years is 160000.

Step-by-step explanation:

The initial population of a town is 1,76,400. It increases at the rate of 5% per annum.

The exponential growth function is

$f(x)=a(1+r)^x$

Where a is initial population and r is increasing rate.

$f(x)=176400(1+0.05)^x$

$f(x)=176400(1.05)^x$

1.

Put x=2, to find the population after 2 years.

$f(x)=176400(1.05)^2=194481$

Therefore the population after 2 years is 194481.

2.

Put x=-2, to find the population 2 years ago.

$f(x)=176400(1.05)^{-2}=160000$

Therefore the population after 2 years is 160000.