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Question
There is a continuous growth in population of a village at the rate of 5% per annum. If its present population is 9,261, what population was 3 years ago?
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Solution
Let P be the population 3 years ago.
Then, present population = P x `(1 + 5/100)^3`
∴ 9,261 = `("P" xx (21)/(20) xx (21)/(20) xx (21)/(20))`
or P = `(9,261 xx (20)/(21) xx (20)/(21) xx (20)/(21))`
= 8,000
Hence, 3years ago the population of village was = 8,000.
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