Question

In January 2020, the population of a town was 5% more than its population in January 2018.
In January 2021, the population of this town was 2% less than its population in January 2020.
Calculate the overall percentage increase in the population from January 2018 to January 2021.

Answer 1

Step-by-step explanation:

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Answer 2

Given,

In January 2020, the population of a town was 5% more than its population in January 2018.

In January 2021, the population of this town was 2% less than its population in January 2020.

To find,

The overall percentage increase in the population from January 2018 to January 2021.

Solution,

We can simply solve this mathematical problem by using the following mathematical process.

Let, the population in January 2018 = x

So,

Population in January 2020 will be :

= (x) + [(x) × (5/100)]

= (x) + (x/20)

= 21x/20

And,

Population in January 2021 will be :

= (21x/20) - [(21x/20) × (2/100)]

= (21x/20) - (21x/1000)

= (1050x -21x)/1000

= 1029x/1000

Population increase from January 2018 to January 2021 :

= (1029x/1000) - x

= (1029x - 1000x)/1000

= 29x/1000

Percentage increase in the population from January 2018 to January 2021 :

= 100 × (increase in population from January 2018 to January 2021 ÷ population in January 2018)

= 100 × [(29x/1000) ÷ x]

= 100 × [(29x/1000) × (1/x)]

= 100 × (29/1000)

= 29/10

= 2.9%

Hence, the population increased by 2.9% from January 2018 to January 2021