Simple Interest worksheets - Free Printable

To solve these problems, we use the simple interest formula:

$$
I = P \times r \times t
$$

Where:
- $ I $ = Interest earned
- $ P $ = Principal (initial amount)
- $ r $ = Annual interest rate (as a decimal)
- $ t $ = Time in years

Then, the ending balance is:

$$
\text{Ending Balance} = P + I
$$

We'll go through each problem step by step.

---

1) $35,100 at 4% for 3 years

$ P = 35100, r = 0.04, t = 3 $
$ I = 35100 \times 0.04 \times 3 = 4212 $
Ending Balance: $ 35100 + 4212 = \boxed{39312} $

---

2) $150 at 5% for 2 years

$ I = 150 \times 0.05 \times 2 = 15 $
Ending Balance: $ 150 + 15 = \boxed{165} $

---

3) $1,400 at 3% for 4 years

$ I = 1400 \times 0.03 \times 4 = 168 $
Ending Balance: $ 1400 + 168 = \boxed{1568} $

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4) $450 at 9% for 8 years

$ I = 450 \times 0.09 \times 8 = 324 $
Ending Balance: $ 450 + 324 = \boxed{774} $

---

5) $2,400 at 5% for 2 years

$ I = 2400 \times 0.05 \times 2 = 240 $
Ending Balance: $ 2400 + 240 = \boxed{2640} $

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6) $600 at 4.5% for 5 months

Convert 5 months to years: $ t = \frac{5}{12} \approx 0.4167 $
$ I = 600 \times 0.045 \times \frac{5}{12} = 11.25 $
Ending Balance: $ 600 + 11.25 = \boxed{611.25} $

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7) $15,600 at 5.5% for 6 years

$ I = 15600 \times 0.055 \times 6 = 5148 $
Ending Balance: $ 15600 + 5148 = \boxed{20748} $

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8) $1,300 at 4% for 3 years

$ I = 1300 \times 0.04 \times 3 = 156 $
Ending Balance: $ 1300 + 156 = \boxed{1456} $

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9) $750 at 5.5% for 5 years

$ I = 750 \times 0.055 \times 5 = 206.25 $
Ending Balance: $ 750 + 206.25 = \boxed{956.25} $

---

10) $850 at 2.2% for 11 months

$ t = \frac{11}{12} \approx 0.9167 $
$ I = 850 \times 0.022 \times \frac{11}{12} = 17.19 $ (rounded to nearest cent)
Ending Balance: $ 850 + 17.19 = \boxed{867.19} $

---

11) $20,600 at 5.5% for 4 years

$ I = 20600 \times 0.055 \times 4 = 4532 $
Ending Balance: $ 20600 + 4532 = \boxed{25132} $

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12) $100 at 2% for 9 months

$ t = \frac{9}{12} = 0.75 $
$ I = 100 \times 0.02 \times 0.75 = 1.50 $
Ending Balance: $ 100 + 1.50 = \boxed{101.50} $

---

13) $4,000 at 4% for 3 years

$ I = 4000 \times 0.04 \times 3 = 480 $
Ending Balance: $ 4000 + 480 = \boxed{4480} $

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14) $7,400 at 2.2% for 9 months

$ t = \frac{9}{12} = 0.75 $
$ I = 7400 \times 0.022 \times 0.75 = 120.15 $
Ending Balance: $ 7400 + 120.15 = \boxed{7520.15} $

---

15) $1,900 at 6% for 3 years

$ I = 1900 \times 0.06 \times 3 = 342 $
Ending Balance: $ 1900 + 342 = \boxed{2242} $

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16) $7,300 at 5.2% for 3 months

$ t = \frac{3}{12} = 0.25 $
$ I = 7300 \times 0.052 \times 0.25 = 94.90 $
Ending Balance: $ 7300 + 94.90 = \boxed{7394.90} $

---

17) $210 at 5.9% for 3 years

$ I = 210 \times 0.059 \times 3 = 36.57 $
Ending Balance: $ 210 + 36.57 = \boxed{246.57} $

---

18) $35,100 at 3.6% for 3 months

$ t = \frac{3}{12} = 0.25 $
$ I = 35100 \times 0.036 \times 0.25 = 315.90 $
Ending Balance: $ 35100 + 315.90 = \boxed{35415.90} $

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✔ Final Answers:

| Problem | Ending Balance |
|--------|----------------|
| 1) | $39,312.00 |
| 2) | $165.00 |
| 3) | $1,568.00 |
| 4) | $774.00 |
| 5) | $2,640.00 |
| 6) | $611.25 |
| 7) | $20,748.00 |
| 8) | $1,456.00 |
| 9) | $956.25 |
| 10) | $867.19 |
| 11) | $25,132.00 |
| 12) | $101.50 |
| 13) | $4,480.00 |
| 14) | $7,520.15 |
| 15) | $2,242.00 |
| 16) | $7,394.90 |
| 17) | $246.57 |
| 18) | $35,415.90 |

Let me know if you'd like this in a printable format or need explanations for any specific one!