Q. 234.2( 22 Votes )

# Three years ago, the population of a town was 50000. If the annual increase during three successive years be at the rate of 5%, 4% and 3% respectively, what is its present population?

Answer :

Population of a town, P = 50000

Interest rate for 1^{st} year, p = 5%

Interest rate for 2^{nd} year, q = 4%

Interest rate for 3^{rd} year, r = 3%

Time, n = 3 years

Now,

Present population = P × (1 + p/100) × (1 + q/100) × (1 + r/100)

= 50000 × (1 + 5/100) × (1 + 4/100) × (1 + 3/100)

= 50000 × (1 + 1/20) × (1 + 1/25) × (1 + 3/100)

= 50000 × 21/20 × 26/25 × 103/100

= 50 × 21/2 × 26/25 × 103

= 1 × 21 × 26 × 103

= 56238

∴ Present population of a town is 56238.

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