A city has a population of 310,000 people. Suppose that each year the population grows by 9%. What will the population be after 13 years?

Answer: 644,800

Step-by-step explanation:

This can also be solved using the terms of Arithmetic Progressions.

Let the 13 years be number of terms of the sequences (n)

Therefore;

T₁₃ = a + (n - 1) d, where a = 310,000 and d = 9% of 310,000

9% of 310,000 = 9/100 x 310,000

= 27,900

so the common difference (d)

d = 27,900

Now substitute for the values in the formula above and calculate

T₁₃ = 310,000 + (13 - 1) x 27,900

= 310,000 + 12 x 27,900

= 310,000 + 334,800

= 644,800.

The population after 13 years = 644,800.