The current population of a city is 11,02,500. If it has been increasing at the rate of 5% per annum, what was its population 2 years ago?

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ELECTRONICE & COMMUNICATION 2021 GATE EXAM 

Question :The current population of a city is 11,02,500. If it has been increasing at the rate of 5% per annum, what was its population 2 years ago?

(A) 9,92,500

(B) 9,95,006

(C) 10,00,000

(D) 12,51,506

ANSWER : C

Current population of a city = 11, 02, 500

Increasing rate = 5%/Annum

The population 2 years ago =?

Let us assume, the population 2 years ago = x

Using compound interest formula,

A =P (1 +R/100) ^n

11,02,500 =x(1+5/ 100)^2

11,02,500*100*100/105*105=x

x =10,00,000

The population 2 years ago = 10,00,000.