Question

If the annual increase in the population of a town is 5% and the present number of people is 50,000. What will be the population in the next year?

Answer 1

Answer:

Present population, P=68590

Let R=5%

The population three years ago

= =

(1−

100

R

)

3

P

=

(1−

100

5

)

3

68590

=

(

20

19

)

3

68590

=

19×19×19

68590×20×20×20

=

6859

548720000

=80,000

Answer 2

Given: Annual increase in the population of a town = 5%

          Present number of people = 50,000

To find: The population in next year

Let: The population in next year be $x$

Solution: According to the given question,

Present population = 50,000

New population = $x$ (assumed)

Rate of increase in population = 5%

Now, If a quantity increases by $y$%, then

∵ new quantity = original quantity + $y$% of original quantity (increase in the quantity)

Similalrly,

∴ New population = present population + 5% of present population

⇒ $x = 50,000 + \frac{5}{100} \ * \ 50,000$

⇒ $x = 50,000 + 2,500 = 52,500$

Hence, the population will be 52,500 in next year.