The population of a city increases at the rate of 5% pa. If the present population of the city is 185220, then what was its population 3 yr ago?


A) 181500

B) 183433

C) 160000

D) 127783

Correct Answer:
C) 160000

Description for Correct answer:

Given, P=185220,R=5% (increases) and n=3yr.

According to the formula,

Population n yr ago = \( \Large  \frac{P}{ \left(1+\frac{R}{100}\right)^{n}} \)

\( \Large  \frac{185220}{ \left(1+\frac{5}{100}\right)^{3}}  = \)\(  \Large \frac{185220\times 20\times 20\times 20}{21\times 21\times 21} \)

=\( \Large 20\times 20\times 20\times 20 \)=160000


Part of solved Compound interest questions and answers : >> Aptitude >> Compound interest








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