Question

A population of 800 cheetahs decreases by 13% per year. How many cheetahs will there be in the population after 5 years? Round your answer to the nearest whole number.

a. 735

b. 399

c. 347

d. 1474

Answer 1

Using the exponential decay formula Y = A(1-r)^t

Where A is the starting value, r is the percent of change and t is the time.

Y = 800(1-0.13)^5

Y = 800(0.87)^5

Y = 800(0.49842)

Y = 398.74 = 399

The answer is B. 399