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2.04 Compound interest using finance solvers

Worksheet
Future value
1

Find the future value of the following investments:

a
\$3000 is invested at an interest rate of 5\% p.a. compounded annually for 17 years.
b
\$2800 is invested at an interest rate of 4\% p.a. compounded quarterly for 15 years.
c
\$10\,000 is invested at an interest rate of 2.7\% p.a. compounded monthly over 18 months.
d
\$15\,000 is invested with at an interest rate of 0.7\% per month compounded monthly for 23 months.
2

Find the future value of the following loans:

a
\$2000 is borrowed at an interest rate of 12\% p.a. compounded monthly for 2 years.
b
\$9000 is borrowed at an interest rate of 3.5\% p.a. compounded half-yearly for 6 years.
c
Ryan borrows \$4000 at a rate of 5.5\% p.a. compounded weekly for 1 year.
d
\$5000 is borrowed at an interest rate of 3.5\% p.a. compounded daily over 4 years.
e
\$3500 is borrowed at an interest rate of 2.4\% per quarter compounded quarterly over 5 years.
f
\$500 is borrowed at an interest rate of 10.7\% p.a. compounded daily for 10 weeks.
3

Skye takes out a car loan of \$32\,000 at an interest rate of 0.01\% per day compounded monthly. How much must she pay back at the end of 5 years?

4

A deposit of \$6000 attracts interest at a rate of 2.5\% p.a. compounded monthly. Find how much is in the account after 3.5 years.

5

Laura has a choice between a high-risk investment which attracts interest at 10\% p.a. compounded annually, or a low-risk investment at 5\% p.a. compounded annually. She has \$50\,000 to invest and her goal is to grow it to \$60\,000 within 3 years.

Which of the investments would allow her to reach her goal, the high risk or the low risk investment?

Interest earned
6

\$2000 is invested at an interest rate of 4\% p.a. compounded quarterly.

a

Find the value of the investment after 15 years.

b

Find the amount of interest earned over the 15 years.

7

\$5000 is borrowed at an interest rate of 12\% p.a. compounded monthly.

a

Find the amount owed after 3 years.

b

Find the amount of interest earned over the 3 years.

8

Find the amount of interest that is earned on the following accounts:

a
\$10\,000 is invested at an interest rate of 2.5\% p.a. compounded monthly over 24 months.
b
\$11\,000 is borrowed at an interest rate of 3.5\% p.a. compounded semi-annually over 30 months.
c
\$900 is borrowed at an interest rate of 10.5\% p.a. compounded monthly over 1.5 years.
d
\$24\,000 is deposited in a savings account which attracts interest at 1.3\% p.a. compounded daily over 9 years.
e
\$12\,000 is invested at an interest rate of 0.4\% per month compounded monthly over 4.5 years.
9

Nadia borrows \$14\,000 at an interest rate of 5.2\% p.a. compounded weekly. If she makes no repayments, find the amount of interest that is owed after 6 years.

10

Luke borrows \$700 at an interest rate of 17\% p.a. compounded daily. Find the amount of interest that is owed after two weeks.

11

Harry borrows \$3300 at a monthly rate of 1.2\% compounded daily. If he pays back the money after one month, find the amount of interest that Harry paid.

12

The final amount owed on a 30-year loan at 4.5\% p.a. compounded annually is \$240\,000. Find the amount of interest paid on the loan.

Present value
13

Katrina has her property investment currently valued at \$700\,000 and she knows that its value increased at a rate of 10\% p.a. compounded annually for the last 20 years. Find the value of her investment at the beginning of the 20 years.

14

A savings account has a balance of \$25\,500 after 10 years of interest at 1.6\% p.a. compounded quarterly. Find the initial deposit.

15

Harry expects to receive a Christmas bonus of \$7000 in 6 months time. His credit card incurs interest at 14\% p.a. compounded weekly with no interest free period. What is the most he can spend now using his credit card and still be able to pay it off using his Christmas bonus?

16

Jack is aiming to save \$35\,000 after 10 years of investing at an interest rate of 0.1\% per week compounded monthly. Find the amount he needs to deposit as a principal.

Interest rate
17

Homer signs up for a loan of \$1000 compounded annually. After 3 years he owes \$2500. What interest rate has the bank been applying per annum? Round your answer to one decimal place.

18

Sharon discovers a credit card debt of \$2100 from a \$1000 purchase she made 2.5 years prior. Assuming the interest was compounded monthly, what interest rate has been applied per annum? Round your answer to the nearest percentage.

19

A \$2000 investment grows to \$4000 over 2 years accumulating interest compounded monthly. Calculate the interest rate per annum that is being applied. Round your answer to one decimal place.

20

What interest rate per annum would be required to double an investment of \$1000 in 2 years, if the interest is compounded daily? Round your answer to one decimal place. Assume there are 365 days in a year.

21

What interest rate per annum would be required to double an investment of \$P in 4 years if the interest is compounded quarterly? Round your answer to one decimal place.

Number of compounding periods
22

\$1000 is placed in a term deposit with a rate of 5\% p.a. compounded annually. How many whole years will it take for the balance to increase in value to at least \$1500?

23

Vanessa borrows \$25\,000 at an interest rate of 4.3\% p.a. compounded annually to pay for her university degree. If she continues into postgraduate study, how many whole years will it take for her debt to reach at least \$40\,000?

24

Nadia invests \$1200 in a term deposit with a rate of 2.3\% p.a. compounded monthly. How many whole months will it take for the investment to increase in value to at least \$1500?

25

Ryan borrows \$800 from the bank at a rate of 0.2\% per week, compounded weekly. How many whole weeks will it take for the amount he owes to increase to at least \$1300?

26

Neil invests \$900 in a term deposit with a rate of 2.3\% p.a. compounded daily. How many years will it take for the investment to at least double in value?

27

How many whole years will it take an investment of \$P to at least double in value if interest at 4.2\% p.a. is compounded quarterly?

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Outcomes

1.1.5

apply percentage increase or decrease in contexts, including determining the impact of inflation on costs and wages over time, calculating percentage mark-ups and discounts, calculating GST, calculating profit or loss in absolute and percentage terms, and calculating simple and compound interest

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