Real-World Problems with Exponential Functions!

Leo invests $200 into an account that earns 4% interest that is compounded daily (365 days in a year). Which equation can be used to answer the question: How much money will be in the account after 7 years?

• $A=200\left(1+\frac{365}{.04}\right)^{.04\left(7\right)}$

• $A=200\left(1+\frac{4}{365}\right)^{365\left(7\right)}$

• $200=P\left(1+\frac{.04}{365}\right)^{365\left(7\right)}$

• $A=200\left(1+\frac{.04}{365}\right)^{365\left(7\right)}$

Jessica deposited $845 into a bank account that earns 7.3% interest that is compounded continuously. Which equation can be used to answer the question: How much money will be in the account after 36 months?

•  $A=845e^{.073\left(3\right)}$  

•  $A=845e^{7.3\left(3\right)}$  

•  $A=845e^{.073\left(36\right)}$  

•  $A=845\left(1+.073\right)^{36}$  

Luke invested some money into a bank account where he earned 5% interest that was compounded quarterly. After 6 years, the account had a balance of $7000. Which equation can be used to determine Luke's initial investment?

• $7000=x\cdot\left(1+\frac{.05}{25}\right)^{25\left(6\right)}$

• $7000=x\cdot\left(1+\frac{.05}{4}\right)^{4\left(6\right)}$

• $A=7000\left(1+\frac{.05}{4}\right)^{4\left(6\right)}$

• $A=7000\left(1+\frac{.05}{25}\right)^{25\left(6\right)}$

Trish deposits $105 into an account that earns 6.1% interest that is compounded continuously. Which equation can be used to answer the question: How long will it take for her investment to double?

• $210=105e^{0.61x}$

• $A=105e^{0.061\left(1\right)}$

• $105=xe^{0.061\left(2\right)}$

• $210=105e^{0.061x}$