4.09 Simple interest
If \$16\,716 of simple interest was earned in 7 years, find how much interest was earned:
Each year
Each month
Ned borrowed \$3600 from a bank at a simple interest rate of 2.5\% p.a.
Calculate the interest on the loan in one year.
Calculate the interest on the loan after three years.
Calculate the total amount Ned will have to repay the bank at the end of 3 years.
Buzz takes out 6-year \$50\,000 loan at 8\% p.a. simple interest.
Calculate the total interest he will have to pay on the loan.
Calculate the total amount he will have to pay back.
Calculate the total simple interest to be paid on a 3-year \$8000 loan at 13\% p.a.
Calculate the total amount to be paid back on a 5-year loan of \$110\,000 at 5\% p.a. simple interest.
Sally pays for her purchase of a new carpet, valued at \$9000, by paying a \$3000 deposit and borrowing the balance at 5\% p.a. simple interest to be repaid over 3 years.
Find the total interest she will have to pay.
Calculate the total amount she will pay for the carpet.
Calculate the simple interest earned on the following investments. Assume that a year has 52 weeks or 365 days.
\$2540 at 9\% p.a. for 2 years
\$2010 at 6\% p.a. for 13 months
\$5320 at 6\% p.a. for 95 weeks
\$5440 at 6\% p.a. for 566 days
\$7000 at 1.8\% per quarter for 9 years
\$1050 at a semiannual rate of 1.1\% for 9 years
Calculate the simple interest charged on the following loans. Assume that a year has 52 weeks or 365 days.
\$8000 at 8\% p.a. for 6 years
\$3860 at 9\% p.a. for 13 months
\$5010 at 5\% p.a. for 666 days
\$5240 at 4\% p.a. for 73 weeks
Calculate the final value of these investments:
\$6170 at 5\% p.a. for 6 years.
\$9060 at 4\% p.a. for 44 months.
\$4230 at 8\% p.a. for 32 weeks.
\$4620 at 6\% p.a. for 146 days.
Bianca takes out a loan of \$800 to pay for an online course. Simple interest is calculated at 9\% per year, charged monthly. If she repays the loan in 9 months, how much interest does she pay in total?
Dave and Emily are looking to invest \$11\,600 and \$18\,300 respectively for 6 years. The table shows the simple interest rates for different principals:
Calculate the interest Dave will earn on his investment.
Calculate the interest Emily will earn on her investment.
| Principal | Rate p.a. |
|---|---|
| \text{Between \$4800 and \$14\,800} | 4\% |
| \text{Between \$14\,800 and \$24\,800} | 5\% |
| \text{Greater than \$24\,800} | 6\% |
How much will they earn if they combine their principals and invest together?
Should they invest separately or together? Explain your answer.
Tara takes out a car loan of \$6000 at a simple interest of 8\% p.a. She plans to repay the loan over 2 years through regular monthly repayments.
Calculate the total interest that Tara will incur over the duration of the repayment.
Calculate the value of each repayment of the loan.
\$402 is invested at 4\% p.a. simple interest for 9 years. After this time the principal plus interest is reinvested at 6\% p.a. simple interest for 8 more years.
Calculate the value of the investment after 9 years.
Calculate the final value of the investment.
Calculate the total amount of interest earned.
Luke's investment of \$3000 earned simple interest of 4\% p.a. for the first 8 years, and 2\% p.a. for the next 5 years.
Calculate the total amount of interest earned.
For each of the following investments find the annual simple interest rate, R, as a percentage rounded to one decimal place.
\$3600 invested over 2 years earns \$504.00
\$4800 invested over 20 months earns \$760.00
\$1600 invested over 3 quarters earns \$103.20
For each of the following loans find the annual simple interest rate, R, as a percentage rounded to one decimal place.
The simple interest on a loan of \$7550 over 9 years is \$6523.20.
The simple interest on a loan of \$5800 over 6 quarters is \$321.90.
The simple interest on a loan of \$5500 over 24 months is \$385.00.
\$1957 is invested at a simple interest rate of 6\% p.a. Calculate the number of years needed for interest of \$1174.20 to be earned on the investment.
\$2379 is invested at a simple interest rate of 2\% p.a. Calculate the number of quarters needed for interest of \$23.79 to be earned on the investment.
For his investment into government bonds, Scott was paid simple interest of 9\% p.a. Calculate the size of Scott's initial investment \$P, if he earned \$294.12 interest after 2 years.
\$63\,790 is invested at a simple interest rate of 8\% p.a. Calculate the number of months needed for interest of \$7654.80 to be earned on the investment. Round your answer to the nearest month.
Lisa made loan repayments totalling to \$4320 on a loan of \$4000 over 4 years.
Calculate the total simple interest charged on the loan.
Calculate the annual simple interest rate.
\$552 is invested at a simple interest rate of 5\% p.a.
Calculate the interest that will be earned on the investment in one year.
Calculate the number of years it will take the investment to grow to \$828.
\$7050 is invested at a simple interest rate of 7\% p.a. Calculate the number of years needed for it to grow to \$7950. Round your answer to two decimal places.
If \$2196 is invested at 2\% p.a. simple interest for 8 years, what simple interest rate R, would earn the same amount of interest in only 5 years?
Express R as a percentage, correct to two decimal places.
The graph shows the amount of simple interest charged each year by a particular bank, on a 3-year loan:
Find the total amount of simple interest charged on a loan of \$5000.
Calculate the simple interest rate per annum charged by the bank on 3-year loans.
The given graph shows an amount of \$4000 deposited into a savings account for 10 years earning simple interest.
How much interest has been earned in total over the 10 year period?
Find the interest rate as a percentage, correct to two decimal places.