Worked examples
Two examples
Example 1
How much simple interest does $2,000 earn at 4% a year for 3 years?
- Simple interest is I = Prt: principal, times rate as a decimal, times years.
- 2,000 × 0.04 × 3 = 240.
Answer: $240.00
Example 2
Ana puts $1,500 in an account that pays 2.5% simple interest a year. How much is in the account after 2 years?
- The interest: 1,500 × 0.025 × 2 = 75.
- Add it to what she put in: 1,500 + 75.
Answer: $1,575.00
Where this is taught: Quiz 19: Percent in the World, “Simple interest”
The drill
Ten problems
This drill also has challenge problems. They use the same skill, set up the way the GED test sometimes sets up a problem, so that it looks new at first.
How many:
Type the amount only, like 12.50; the unit is already there. Then press Check my answers at the bottom.Write each answer on the line. The answer key, with the reasoning, is on the last page.