Question

The population of a town increases 5% in the first year and decreases 4% in the second year the population was 360,000 at the beginning of the first year what is the population at the end of 2 years

Answer 1

Answer:

increase rate 5℅

then decrease rate 4%

360000×5÷100=18000

then the population is =360000+18000=378000

decrease=378000×4÷100=15120

two years after populations=378000-15120=362880

Answer 2

GIVEN :-

• Population of town at beginning is 360000.

• Population increases by 5% in 1st year and decreases by 4% in 2nd year.

TO FIND :-

• Population after 2 years.

APPROACH :-

• We will 1st find the increase in population (by 5%) for the 1st year. Then again , we will find population when it is decreased(by 4%) for the 2nd year.

SOLUTION :-

For the 1st year , Population is increased by 5%.

Population = 360000 + (5% of 360000)

$\\ \implies \sf \: 360000 + \frac{5}{ \cancel{100}} (3600 \cancel{00}) \\ \\ \implies \sf \: 360000 + 5(3600) \\ \\ \implies \sf \: 360000 + 18000 \\ \\ \implies \boxed{\sf \: population \: after \: 1year = 378000}$

Population is decreased by 4% for the 2nd year.

Population = 378000 - (4% of 378000)

$\\ \\ \implies \sf \: 378000 - \frac{4}{ \cancel{100}}(3780 \cancel{00}) \\ \\ \implies \sf \: 378000 - 4(3780) \\ \\ \implies \sf \: 378000 - 15120 \\ \\ \implies \boxed{ \sf \:population \: after\: 2years = 362880}$

Hence , population after 2 years is 362880.