Interest Percent

Write an equation that models the following situation:
Samantha's hair was known to grow very rapidly. It began at a length of 6 in and grew at a rate of 14% a week.

• y=6(0.14)^x

• y=6(1+14)^x

• y=6(1.14)^x

• y=6(0.86)^x

Which of the following functions shows an initial amount of $15 and an increase of 35% each year?

• y = 15(35)^x

• y = 15(1.35)^x

• y = 15(0.35)^x

• y = 35(1.15)^x

A new savings account is opened with $400 and gains 3% every year. What is the exponential function?

• f(x)=400(3)^x

• f(x)=400(0.97)^x

• f(x)=400(1.03)^x

• f(x)=400(0.03)^x

Caiden earned $475 from mowing lawns last summer. He deposited this money in an account that pays a simple interest rate of 3.8%. What will be the amount of interest earned after 15 years?

• $3182.50

• $270.75

• $2707.50

• $745.75

Jane deposited $22,000 at a bank that pays 10% interest. Bill deposited $16,000 at a bank that pays 16% interest. Who will receive more interest in a year, and by how much more?

You lend $240 to your friend. He pays you back $270 in one year . What interest rate did you charge your friend?

• 88%

• 20%

• 12.5%

• 10%

Principal = $800
Interest Rate = 3.5%
Time = 6 months
Find the interest earned.

• 14

• 140

• 168

• 16.80

There are 75 students in the school band.  45 students play woodwind instruments.  What percent of students play woodwinds?

• 35%

• 60%

• 55%

• 70%

What is 35% of 180?

• 63

• 70

• 75

• 80

Emily’s parents put $1500 in her bank account for college tuition at a simple interest rate of 8.25%. What will be the balance after 18 years?

• $22,275

• $2227.50

• $12,375

• $3727.50