The population in Kingstown decreases by 30% each month. By what percent did the original population decrease after 2 months? A. 40% B. 49% C. 51% D. 60%

C. 51%

Step-by-step explanation:

Let P represent the original population.

Given that the population decreases by 30% monthly

After one month P would have decreased

P - 30%P = P (1 - 0.3)

The population at time t months can be written as;

P (t) = P (1 - 0.3) ^t

P (t) = P (0.7) ^t

For t = 2 months

P (2) = P (0.7) ^2

P (2) = P (0.49)

P (2) = 49% of P

Therefore, the population have decreased by

∆P = P - P (2) = P - 49% of P = P (100% - 49%)

∆P = 51% of P

The population have decreased 51%