Exercises
1. POPULATION The population of Bulgaria has been decreasing at an annual
rate of 0.89%. If the population of Bulgaria was about 7,450,349 in the year
2005, predict its population in the year 2015.
2. DEPRECIATION Mr. Gossell is a machinist. He bought some new machinery for about
$125,000. He wants to calculate the value of the machinery over the next 10 years for
tax purposes. If the machinery depreciates at the rate of 15% per year, what is the value
of the machinery to the nearest $100) at the end of 10 years?
3. ARCHAEOLOGY The half-life of a radioactive element is defined as the time that it
takes for one-half a quantity of the element to decay. Radioactive carbon-14 is found in
all living organisms and has a half-life of 5730 years. Consider a living organism with an
original concentration of carbon-14 of 100 grams.
a. If the organism lived 5730 years ago, what is the concentration of carbon-14
today?
b. If the organism lived 11,460 years ago, determine the concentration of carbon-14
today
4. DEPRECIATION A new car costs $32,000. It is expected to depreciate 12% each year
for years and then depreciate 8% each year thereafter. Find the value of the car in
6 years
Glencoe Algebra 1