Solve the problem.
-There are currently 57 million cars in a certain country, increasing exponentially by 0.8% annually. How many years will it take for this country to have 64 million cars? Round to the nearest year.
A)14 yr
B)5 yr
C)243 yr
D)9 yr

Question

Quizplus · Accepted Answer

The number of cars grows according to the formula $N = N_0 \cdot (1 + r)^t$, where $N$ is the future amount, $N_0$ is the initial amount, $r$ is the rate of growth, and $t$ is time in years. Plugging in the given values: $64 = 57 \cdot (1 + 0.008)^t$. Solving for $t$ gives approximately 14 years.

Solve the Problem. -There Are Currently 57 Million Cars in a Certain Country