Percent of Change and Simple Interest

The simple interest formula is I=Prt.  The P represents the principle.  The principle is ___________________.  

• the amount of money borrowed or deposited

• the percent interest for his year

• the amount taxed

• the amount the bank owes you for being a customer at their bank

Frank has earned $387 in interest over the past 36 months in his account. If the bank has a 1% interest rate, how much was the principal? 

• $12,900

• $1,290

• $129,00

A pair of shoes is originally $54 and on sale for $45.90.

What is the percent of change.

You took out a car loan for $25,000 and paid $3,750 in simple interest. You paid the loan off in 5 years. What was the interest rate?

Find the percent change.

Original amount: 72

New amount: 7

• 20% increase

• 90% increase

• 10% decrease

• 90% decrease

One week, 72 people got a speeding ticket. The next week, only 36 people got a speeding ticket. What is the percent of change in the speeding tickets?

• Increase 50%

• Decrease 50%

• Increase 1%

• Decrease 1%

Last week, you finished level 2 of a video game in 32 minutes. Today, you finished level 2 in 28 minutes. What is your percent of change?

• Increase 12.5%

• Decrease 12.5%

• Increase 4%

• Decrease 4%

Christian opened a savings account with $3250. His account will earn 5.2% simple interest. How much money will be in his account after 6 years?

• $4,264.00

• $1,104.00

• $1,100.00

• $4,400.00

Alexis opened an account with $35. The account she opened earns simple interest at a rate of 8.6%. How much money will her account have in 4 years?

• $47.04

• $35.04

• $45.00

• $37.45

Tickets to Disney World are $100.The price is going to increase on January 1. What is the percent of change if the cost increases to a $120?

• 25%

• 18%

• 20%

• 50%