Question

The population of a town increases every year by 2% of the population at the beginning of
year. The number of years by which the total increase of population be 40% is
(c) 17 years (app)
that
(a) 7 years
(b) 10 years
(d) none of these​

Answer 1

Answer:

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Applying compounding or iteration formula,

(1+40/100)=(1+2/100)^t where t is no. years.

So t=Ln (1+40/100)/1+2/100)

t = Ln1.4/Ln1.2, From Logarithm table

t = 0.336472/0.019803=16.99129 Yrs (ie.17Years)

So 17 years is the answer