Question

Worksheet 4
1.
The population of a town is increasing at the rate of 8% per annum. What will be
the population of the town after two years if the present population is 12,500?
2. Three years ago, the population of a town was 50,000. If the annual increase
during three successive years was at the rate 4%, 5% and 4% per annum
respectively, find the present population.
3. Madhu bought a house for * 1,31,25,000. If its value depreciates at the rate of
N°10% per annum, what will be its sale price after three years?
4. The profits of a firm were 72,000 in the year 2014. During the next year,
it increased by 7% and it decreased by 5% in the following year. What are the
profits of the firm after two years?
The population of a town is 64,000. If the annual birth rate is 10.7% and the
N'annual death rate is 3.2%, calculate the population after three years.
[Hint: Net growth rate = (Birth rate - Death rate)%]
6.
In a factory, the production of motor bikes was 40,000 in a particular year, which
rose to 48,400 in two years. Find the rate of growth per annum, if it was uniform
during two years.​

Answer 1

Answer:

The exponential growth equation is given by :-

y=A(1+r)^xy=A(1+r)

x

, where A is initial amount , r is rate of growth and x is time period.

Given : Rate : r= 8% = 0.08

Present population = 12500

Time period : x=2 years

Then, the population of the town after 2 years :-

\begin{gathered}y=12500(1+0.08)^2\\\\\Rightarrow\ y=12500(1.08)^2=12500(1.1664)\\\\=14580\end{gathered}

y=12500(1+0.08)

2

⇒ y=12500(1.08)

2

=12500(1.1664)

=14580

Hence, the population of the town after 2 years = 14,580

if it is useful to you mark it as brailliest