naveed_786110
New member
- Joined
- May 10, 2015
- Messages
- 26
Q. The population of a country is growing exponentially at a constant rate of 2% per year. How much time this population will take to double itself?
Solution:
Method-I:
S=P(1+i)^n
2P=P(1+0.02)^n
2 = 1.02^n
n=log 2 / log 1.02
n=35 years.
Method - II:
S=Pe^in
2P=Pe^0.02n
n=34.65
The correct answer is 34.65..... The problem is why METHOD - I is not working (even its close) ?
Solution:
Method-I:
S=P(1+i)^n
2P=P(1+0.02)^n
2 = 1.02^n
n=log 2 / log 1.02
n=35 years.
Method - II:
S=Pe^in
2P=Pe^0.02n
n=34.65
The correct answer is 34.65..... The problem is why METHOD - I is not working (even its close) ?