Over Lesson 7–6

TAXES Martina bought a new pair of shoes. Her receipt is shown below. She wants to know the sales tax rate, but she spilled water on the receipt, blurring the information. What is the sales tax rate in Martina’s state?

You have already solved problems using the percent proportion.

• Solve simple interest problems and apply the simple interest equation to real-world problems.

• Solve compound interest problems.

• simple interest – interest paid only on the initial principal

Find Simple Interest

A. Find the simple interest for $2000 invested at 2.5% for 3 years.

I = prt Write the simple interest formula.

I = 2000 ● 0.025 ● 3 Replace p with 2000, r with

0.025, and t with 3.

I = 150 Simplify.

Answer: The simple interest is $150.

Find Simple Interest

B. Find the simple interest for $4500 invested at 4.25% for 24 months.

I = prt Write the simple interest formula.

I = 4500 ● 0.0425 ● 2 Replace p with 4500, r with 0.0425, and t with

2.

I = 382.50 Simplify.Answer: The simple interest is $382.50.

The loan will be for 24 months or 2 years, so t = 2

A. $105

B. $150

C. $210

D. $350

A. What is the simple interest for $3000 invested at 3.5% for 2 years?

A. $137.50

B. $275

C. $302.75

D. $412.50

B. What is the simple interest for $2500 invested at 2.75% for 48 months?