Question

The population of a village is 80000 at present, If every year in some family member of village new babies are born due to which population of village is increased by 20% each year. What will be the population of village after two years.?
1. 115200
2. 112500
3. 110025
4. 10125

Answer 1

Correct Answer - Option 1 : 115200

Given

The population of a village is 80000 at present.

Increased by 20% each year.

Concept 

For two years.

New Population = [Present age × (Increased percent) × (Increased percent)]

Calculate 

⇒ Increased in population = 80000 × (20/100)

⇒ Increased in population = 16000

⇒ Population of village for first year after increment = 80000 + 16000

⇒ Population of village for first year after increment = 96000

Now,

⇒ For second year increased in population = 96000 × (20/100)

⇒ For second year increased in population = 19200

⇒ Population of village for second year after increment = 96000 + 19200

⇒ Population of village for second year after increment = 115200

⇒ After two years population of village becomes = 115200

∴ After two years population of village becomes = 115200

Alternate method 

⇒ New population = [80000 × (120/100) × (120/100)]

⇒ New population = 115200 

∴ New population 115200