5.07 Simple interest
If \$16\,716 of simple interest was earned in 7 years, find how much interest was earned:
Each year
Each month
Calculate the simple interest earned on the following investments. Assume that a year has 52 weeks or 365 days.
\$1030 at 8\% p.a. for 2 years.
\$8510 at 7\% p.a. for 25 months.
\$7200 at 2\% p.a. for 101 weeks.
\$6730 at 7\% p.a. for 33 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 generated on the following loans. Assume that a year has 52 weeks or 365 days.
\$9300 at 2\% p.a. for 6 years.
\$8910 at 9\% p.a. for 7 months.
\$7580 at 6\% p.a. for 13 months.
\$9040 at 7\% p.a. for 41 weeks.
\$7180 at 6\% p.a. for 193 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?
Calculate the value of these simple interest investments. Assume that a year has 52 weeks or 365 days.
\$5400 at 8\% per year for 4 years.
\$3840 at 5\% per year for 30 months.
\$1500 at 4\% per year for 101 weeks.
\$5480 at 6\% per year for 275 days.
Rosey takes out a car loan of \$5000 at a simple interest of 5\% per year. She plans to repay the loan over 4 years through regular monthly repayments.
Calculate the total interest that Rosey will incur over the duration of the repayment.
Now, calculate the value of each repayment of the loan.
\$413 is invested at 3\% per year simple interest for 6 years. After this time the principal plus interest is reinvested at 5\% per year simple interest for 4 more years.
Find the value of the investment after 6 years.
Find the final value of the investment.
Now, how much interest was earned in total?
James's investment of \$3000 earned simple interest of 2\% per year for the first 10 years and 6\% per year for the next 7 years. Calculate the total amount of interest earned.
For his investment into government bonds, Dave was paid simple interest of 3\% per year Calculate the size of Dave's initial investment \$P if he earned \$517.20 interest after 10 years.
Scott and Kirsten are looking to invest \$15\,600 and \$26\,700 respectively for 9 years. The table below shows the simple interest earned for different principals.
| Principal | Rate per year |
|---|---|
| \text{Between } \$7400 \text{ and } \$17,400 | 3\% |
| \text{Between } \$17,400 \text{ and } \$27,400 | 4\% |
| \text{Greater than } \$27,400 | 5\% |
Find the interest will Scott earn on his investment.
Find interest will Kirsten earn on her investment.
Find the interest they will earn if they invest their principals together.
How much more interest will they earn by combining their principals?
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.
Lisa made loan repayments totaling 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.
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.
If \$4881 is invested at 7\% per year simple interest for 7 years, at what simple interest rate, r, would it need to be invested for, 5 years to earn the same amount of interest? Express your answer as a percentage correct to two decimal places.
\$848 is invested at 8\% per year simple interest. Dave wants to know the number of years it will take the investment to grow to \$1458.56.
Calculate the interest that will be earned on the investment.
Now, calculate the number of years, t, it will take the investment to grow to \$1458.56.
For each of the following investments find the number of years, t, correct to two decimal places.
\$9177 at 10\% p.a. and earns \$3670.80 in interest.
\$6130 at 5\% and grows to \$6350.
\$3973.00 needs to be invested at a simple interest rate of 3\% per year to earn \$148.99 in interest.
Calculate the number of years, t, taken to earn the interest. Round your answer to two decimal places.
Now, find the number of quarters taken to earn the interest.
\$85\,620 needs to be invested at a simple interest rate of 7\% per year to earn \$8990.10 in interest.
Find the number of years, t, taken to earn the interest.
Now, find the number of months taken to earn the interest. Round your answer to the nearest month.