Assignment # ______Finding Simple Interest Name ______
Standard: 1.7 Finding Simple Interest Pre-Algebra, Period ______
Date ______
Interest = Principal x Rate x Time
I = PRT
Mr. Lau’s class deposited $300 in a savings account for 6 months. The money earns 8% simple interest. How much interest will the class receive after 6 years?
Principal: $300 I = 300 x 0.08 x 6
Annual Rate: 8% I = 144
Time: 6 years
Interest: $144
Balance: P + I = $444.
Find the amount of simple interest earned AND the final balance.
Principal: $200 Principal: $500
Annual rate: 9% Annual rate: 6%
Time: 1 year Time: 4 years
1. Interest: ______3. Interest: ______
2. Balance: ______4. Balance: ______
Principal: $450 Principal: $520
Annual rate: 4% Annual rate: 2%
Time: 5 years Time: 3 years
5. Interest: ______7. Interest: ______
6. Balance: ______8. Balance: ______
Mr. Gade deposited $650 and received an annual interest rate of 8%. He kept his money in the bank for two years. How much interest did he receive and what was his final balance?
9. Interest: ______
10. Balance: ______
Mr. Iwawaki deposited $800 and received an annual interest rate of 7%. How much interest would he earn after 5 years?
11. Interest: ______
12. Balance: ______
Mr. Lau’s credit card company charges 20% simple interest. How much would he pay if he has a balance of $360 by the end of the year?
13. Interest: ______
14. Balance: ______
Questions involving discount and tax.
15. Mr. Szot bought computer speakers that were on sale for 35% off the original price. If the speakers originally cost $60, how much was deducted from the original price?
16. What is the sale price for the speakers in the question above (#15)?
17. The sales tax on the speakers is 9%. What’s the total cost of the speakers using the sale price from question #16?
18. You’re shopping for a guitar and find one with an original price of $160. The store is offering a 30% discount on all guitars. Wait! There is an additional 25% off all purchases. What is the sale price of the guitar?