1. Simple Interest
The simple interest formula is often abbreviated in this form: I = P R T Three other variations of this formula are used to find P, R and T:

2. Figure the simple interest
I = P R T
P=1,500
R=3%
T=3 years
1500 x .03 x 3
135

3. You invested $800 at 3% and earned $50. How long did it take?
P=800
R=3%
T=? 50
800 x .03
2.08 Years

4. You invested $900 for 2 years and earned $30. What was the rate?
P=900
T=2
R=? 30
900 x 2
1.67%

5. You invested $1,400 for 2 years at a rate of 4. 5%
You invested $1,400 for 2 years at a rate of 4.5%. It is compounded annually. How much interest did you earn?
I = P R T
Year x .045 x 1 = 63
Year x .045 x 1 = 65.84
Interest Earned: = $128.84

6. Your loan was for $1,000 for 1 year at a rate of 4%
Your loan was for $1,000 for 1 year at a rate of 4%. It is compounded semi-annually. How much did you have to pay back all together?
Year x .04 x .5 = 20
Year x .04 x .5 = 20.40
Total To Pay Back: 1, =