The population in a city was 95,00,000. It has been predicted that in next years the population will decrease at the rate of 20%. What will be the population of city after 4 years?

Correct option is D

Given:

1. Current population: 95,00,000
2. Annual rate of decrease: 20% 
3. Time period: 4 years
4. Population after 4 years is to be calculated.

Formula Used:

The population after n years with a percentage decrease is calculated using the formula for compound decay:
​$$P = P_0 \times (1 - r)^t$$​
Where:
- P : Population after t years.
- $$P_0$$​ : Initial population.
- r : Rate of decrease (as a decimal).
- t : Time period (in years)

Solution:

1. Initial population ( $$P_0$$​) = 95,00,000 
2. Rate of decrease ( r ) = 20% = 0.20 
3. Time period ( t ) = 4 

Substitute the values into the formula:
​$$P = 95,00,000 \times (1 - 0.20)^4$$​
​$$P = 95,00,000 \times (0.80)^4$$​

Calculate $$(0.80)^4$$​ :
​$$(0.80)^4 = 0.4096$$​

Now calculate P :
P = 95,00,000 \times 0.4096
P = 38,91,200

Final Answer:

The population of the city after 4 years will be 38,91,200 

Correct Option: (D) 38,91,200