Practice Simple Interest in Math
Use these practice problems to test your method after reviewing the concept explanation and worked examples.
Quick Recap
Simple interest is interest calculated only on the original principal amount, using the formula .
You lend someone \$100 and they pay you \$5 every year as a thank-you — the \$5 never changes because it is always based on the original \$100.
Showing a random 20 of 50 problems.
Example 1
mediumHow long until \$500 at 4% earns \$60 simple interest?
Example 2
challengeHow many years for any principal to double at 4% simple interest?
Example 3
easyFor 3 months, what value of (in years) do you use?
Example 4
easyFind the simple interest on \$600 at 4% for 1 year.
Example 5
mediumFind the total amount for $800 at 6% for 2 years.
Example 6
hardAt what simple-interest rate will \$800 grow to \$1040 in 6 years?
Example 7
easyWhat does stand for in ?
Example 8
mediumWhat principal earns \$45 at 5% in 3 years (simple)?
Example 9
hard\$3200 at simple 6% — what does the loan total after 2 years and 6 months?
Example 10
challengeA loan of $1500 charges simple interest. After 2 years it grows to $1620; after 5 years to a total of $X. Find .
Example 11
medium\$400 earns \$48 simple interest in 2 years. Find the annual rate.
Example 12
easyFor 6 months, what value of (in years) do you use?
Example 13
mediumWhat principal earns \$120 at 4% in 5 years (simple)?
Example 14
easyWhat is the simple interest on any principal at 0% for 10 years?
Example 15
easyInterest \$30 on \$300 for 1 year — what is the rate?
Example 16
medium\$1200 at 5% simple interest for 18 months. Find the interest.
Example 17
easyFind the simple interest on \$200 at 6% for 5 years.
Example 18
easyStep-by-step: find the simple interest on \$800 at 5% for 3 years.
Example 19
easyFind the simple interest on \$1000 at 3% for 2 years.
Example 20
medium\$1500 grows to \$1800 in 4 years (simple). Find the annual rate.