Compound Interest - Year 9

Compound Interest

By; Yashasvi Awasthi

Simple Interest v/s Compound Interest

• Simple interest; Paid or received over a certain period is a fixed percentage of the principal amount that was borrowed or lent.

• Compound interest; Accumulate and is added to the accumulated interest of previous periods; it includes interest on interest, in other words.

Difference?

Simple Interest & Compound Interest

Formula of Simple Interest

Formula of Compound Interest

Let's Practice!!

Multiple Choice

In the compound interest formula A=P(1+r)^t what does the A stand for?

• The amount of interest

• The total amount

• The interest rate

• The time

Multiple Choice

In the compound interest formula A=P(1+r)^t what does the P stand for?

• The time

• The total amount

• The principal amount (original amount)

• The interest rate

Multiple Choice

Jacob borrows $500 from Abraham and agrees to have the loan compounded annually for 5 years with an interest rate of 2.5%. How much will the total amount be that Jacob owes?

• $565.70

• $262609.38

• $65.70

• $630.20

Multiple Choice

Hei-Hei has $1500 in a retirement account earning 5% interest compounded annually. After 5 years how much does Hei-Hei have in the account?

• $1750

• $2010.14

• $2500

• $1914.42

Multiple Choice

Henry deposits $750 into a college savings account that is compounded annually when his parents received as a stimulus package. If Henry lets the money sit in the account without adding or removing any and receives a 8.5% interest rate, how much money will he have total after 5 years?

• $1127.74

• $1535.24

• $2345.67

• $850.76

Multiple Choice

If you wanted to amount of interest an account has earned after being compounded annually. What would you have to do after you found "A" using the formula A=P(1+r)^t ?

• Add A (total amount) plus P (original amount)

• Subtract A (total amount from P (original amount)

• Add P (original amount) plus A (total amount)

• Subtract P (original amount) from A (total amount)

Multiple Choice

Julia invested $1000 for college in an account earning 5% compounded annually. When she checked the account after 4 years, how much money did she find in the account?

• Not enough

• $563.24

• $1215.51

• $3200.12

Multiple Choice

Trevor wants to have $4000 saved up in 3 years for a car. If he invests $1500 in a savings account that is compounded annually at an interest rate of 12%, will he have enough money at the end of the 4 years?

• Yes

• No

Multiple Choice

Chris borrows $450 from Gavin. Gavin lets Chris choose either a simple interest loan for 10 years with a 3.5% interest rate or a loan compounded annually for 7 years with a 2% interest rate. Which should Chris choose if he wants the cheaper plan? Use I=P*r*t for simple interest (make sure to add I plus P at the end) and A=P*(1+r)^t for compound interest.

• The simple interest plan

• The compound interest plan

Multiple Choice

Daniel invests $360 in a bank account that is compounded annually for 8 years with an interest rate of 5.5%. What will be the total amount in the account after the 8 years is over?

• $625.88

• $950.12

• $315.45

• $552.49

Multiple Choice

Caiden earned $475 from mowing lawns last summer.He deposited this money in an account that pays an interest rate of 3.8% compounded annually. What will be his balance after 15 years?

• $827.52                     (Mr. Williams)       
• $831.10                 (Mrs. Hoch)
• $839.45                    (Mr. Krajunus)
• $846.80                   (Ms. Palombo)

Multiple Choice

To earn as much interest as possible, you should open a savings account that earns ______ interest and has the _____ interest rate.

• compound; lowest
• simple ; lowest
• compound ; highest
• simple ; highest