Hey there!
When the value of something goes down over time- a house, a car, anything- it's called depreciation.
It would be expressed as exponential decay. This is because the value is going down exponentially as stated in the problem. Additionally, when it decays, the growth factor is less than one, so the value steadily decreases.
Let's rule out our other options:
B) Half-Life. This doesn't work because it's usually used for radioactive decay, which is usually a steady decrease of radioactivity and material that divides by two, hence the word half. For example:
Day 0) Started with 10 grams of plutonium
Day 1) 5 grams
Day 2) 2.5 grams
And so on.
C) Compound Interest. Like simple interest, but compunds usually at a certain point - yearly, monthly, every ten years, and so on. But, this is used for interest, mostly in a bank account or if you have a loan. It doesn't exhibit depreciation, and therefore it's not used to predict car value.
D) Exponential Growth- Exponential growth does not work for one main reason - it grows. That would mean that the value of the car goes up- and unless it's an old and very expensive car, that wouldn't be the case.
Hope this helps!
Answer:
$ 850
Step-by-step explanation:
Martha and her brother started their own car-washing business.
We need to use front-end estimation to find out about how much their business will earn in 5 weeks.
Amount charged per car = $8.50
Number of cars washed per weekend = 22
Therefore, amount earned per weekend = Amount charged per car × Number of cars washed per weekend = 8.50 × 22 = $ 187
Amount earned in 5 weeks = amount earned per weekend × 5 = 187 × 5 = $ 935
Therefore, their business will earn $ 935 in 5 weeks.
