Questions: During the worst periods of hyperinflation in a certain country, the price of food increased at a rate of 15% per month. State whether this increase was linear or exponential. If your food bill was 120 in one month during this period, what was it three months later?
Was the growth in inflation linear or exponential?
- linear
- exponential
What was the monthly food bill after three months?
(Round to the nearest dollar as needed.)
Transcript text: During the worst periods of hyperinflation in a certain country, the price of food increased at a rate of $15 \%$ per month. State whether this increase was linear or exponential. If your food bill was $\$ 120$ in one month during this period, what was it three months later?
Was the growth in inflation linear or exponential?
linear
exponential
What was the monthly food bill after three months?
\$
(Round to the nearest dollar as needed.)
Solution
Solution Steps
To determine whether the increase in the price of food is linear or exponential, we need to consider the nature of the percentage increase. A constant percentage increase per time period indicates exponential growth. To find the food bill after three months, we apply the formula for exponential growth, which is the initial amount multiplied by (1 plus the rate of increase) raised to the power of the number of periods.
Step 1: Determine the Nature of the Increase
The price of food increases at a rate of \( 15\% \) per month. Since this is a constant percentage increase, the growth is classified as exponential.
Step 2: Apply the Exponential Growth Formula
To find the food bill after three months, we use the exponential growth formula: