Question

Identify the exponential function that correctly fits the situation below.

The size of a rainforest is currently decreasing at a rate of 17% per year. If there are currently 230,000 square miles of rainforest, then about how many square miles of rainforest will there be in t years?

A.
F = 230,000(0.17)t
B.
F = 230,000(0.83)t
C.
F = 230,000(1.17)t
D.
F = 230,000(1.83)t

Answer 1

The correct answer is B). Indeed, after the first year, we are going to left out with 230,000 * 0.83 square miles of rainforest. It can be modelled with a function according to this example. Then, the answer is:
                                   $230,000*(0.83)^{t}$