Question

Population of a town is 3,60,000. The birth rate is 5.8% per annum and the death rate is 3.8% per annum . What will be the population of the town be after 3 years?

please give the answer step by step.

Answer 1

6,27,000 people because 11.25% is the birth rate which equals 67500 people and 6.75 the total death rate which equals 40500 people ..So 67500-40500=27000
therefore population = 627500

Answer 2

Method - 1:

Given population of a town = 360000.

Rate of increase in population = (5.8 - 3.8) = 2%.

Time n = 3 years.

We know that A = P(1 + r/100)^n

= > A = 360000(1 + 2/100)^3

= > A = 360000(1 + 1/50)^3

= > A = 360000(51/50)^3

= > A = 360000(132651/125000)

= > A = 382034.8.

Therefore, the population of the town after 3 years = 382034.8

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Method - 2:

Given population = 360000

Rate of increase = 5.8 - 3.8 = 2%.

Time n = 3 years.

Now,

Increase  of population in 1st year = (2/100) * 360000 = 7200.

Population at the end of first year = 360000 + 7200 = 367200.

Increase of population in 2nd year = (2/100) * 367200 = 7344.

Population at the end of second year = 367200 + 7344 = 374544

Increase of population in 3rd year = (2/100) * 374544 = 7490.88

Population at the end of third year = 374544 + 7490.88 = 382034.8.

Therefore, the population after 3 years = 382034.8.

Hope this helps!