1. Finding Appreciation or Depreciation

2. Appreciation Depreciation
In situations like growth of population, growth of bacteria, increase in the value
of an asset, increase in price of certain valuable articles, etc., the following
formula is used.
Where p is the present value , r is the rate of increase, n is number of years
Depreciation
In certain cases where the cost of machines, vehicles, value of some articles,
buildings, etc., decreases, the following formula can be used.
Where p is the present value , r is the rate of decrease, n is number of years

3. Example 1: The population of a village increases at the rate of 7% every year. If
the present population is Rs 90,000 what will be the population after 2 years?
Solution Given:- Present population (P) = Rs 90,000, Rate of increase (r) = 7%
To Find :- Population after 2 years (A)
The population after ‘n’ years
The population after 3 years =
Ans:- The population after two years is Rs 1,03,041

4. Example:2 The value of a machine depreciates by 5% each year
Example:2 The value of a machine depreciates by 5% each year. A man pays
Rs 30,000 for the machine. Find its value after three years.
Solution: Given:- Present value of the machine(P) = Rs 30,000,
Rate of depreciation(r) = 5%, Number of years(n) = 3
To Find:- Machine value after three years(D)
The value of the machine after ‘n’ years
The value of the machine after three years =
Ans:-The value of the machine after three years is Rs 25,721.25

5. Example 3: The population of a village has a constant growth of 5% every year. If
its present population is 1,04,832, what was the population two years ago?
Solution:- Given:- Present population(A) = 1,04,832
Rate of increase(r) = 5% , Number of years(n) = 2
To Find:- population two years (P)
Let P be the population two years ago.
≈ 95,086 (rounding off to the nearest whole number)
Answer: Two years ago the population was 95,086.

6. Try these
1. The population of a village increases at the rate of 5% every
year. If the present population is 60,000, what will be the
population after 2 years?
2. The value of a machine depreciates by 7% each year. A man
pays Rs.40,000 for the machine. Find its value after two years.