Algebra 1 | Unit 5 | Lesson 15: Functions Involving Percent Change | Practice Problems

In 2011, the population of deer in a forest was 650. In 2012, the population increases by 15%. Write an expression, using only multiplication, that represents the deer population in 2012.

In 2013, the population increases again by 15%. Write an expression that represents the deer population in 2013.

If the deer population continues to increase by 15% each year, write an expression that represents the deer population \(t\) years after 2011.

Technology required. One $1,000 loan charges 5% interest at the end of each year, while a second loan charges 8% interest at the end of each year. Use technology to create graphs representing \(b\) and \(c\) over time. The graph should show the starting balance of each loan as well as the amount of the loan after 15 years. Write down the graphing window needed to show these points.

A person loans his friend $500. They agree to an annual interest rate of 5%. Write an expression for computing the amount owed on the loan, in dollars, after \(t\) years if no payments are made.

• A: A population of bacteria begins at 15,000. The population triples each hour. How many bacteria are there after 5 hours?

• B: A population of bacteria begins at 15,000. The population triples each hour. How many thousand bacteria are there after 5 hours?

• C: A population of bacteria begin at 15,000. The population quintuples each hour. How many thousand bacteria are there after 3 hours?

• D: A bank account balance is $15. The account balance triples each year. What is the bank account balance, in dollars, after 5 years?

• E: A bank account balance is $15,000. It grows by $3,000 each year. What is the bank account balance, in thousands of dollars, after 5 years?

Here are graphs of two exponential functions, \(f\) and \(g\). If \(f(x) = 100 \times \left(\frac{2}{3}\right)^x\) and \(g(x) = 100 \times b^x\), what could be the value of \(b\)?

• C: 1