Simple interest quiz with a twist

Each question comes with multiple choices—try to answer first, then check the solution after!

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1. Emily borrowed $2,000 at a rate of 6% for 4 years. What is the total interest?

A. $360
B. $480
C. $540
D. $600

Formula:

$$\text{Interest} = 2000 \times 0.06 \times 4 = \boxed{480}$$

✅ Correct Answer: B. $480

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2. Jack invested $1,500 for 2 years and earned $180 in interest. What was the rate?

A. 5%
B. 6%
C. 8%
D. 12%

$$\text{Rate} = \frac{180}{1500 \times 2} = 0.06 = \boxed{6\%}$$

✅ Correct Answer: B. 6%

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3. A loan of $800 earns $96 in interest at 4% interest. How long was the loan?

A. 2 years
B. 3 years
C. 4 years
D. 5 years

$$\text{Time} = \frac{96}{800 \times 0.04} = \frac{96}{32} = \boxed{3}$$

✅ Correct Answer: B. 3 years

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4. Sarah paid $525 in interest on a 5-year loan at 7%. What was the original principal?

A. $1,200
B. $1,400
C. $1,500
D. $1,700

$$\text{Principal} = \frac{525}{0.07 \times 5} = \frac{525}{0.35} = \boxed{1500}$$

✅ Correct Answer: C. $1,500

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5. Tom earned $600 in interest over 3 years at 10%. How much did he invest?

A. $1,800
B. $2,000
C. $2,400
D. $2,800

$$\text{Principal} = \frac{600}{0.10 \times 3} = \frac{600}{0.30} = \boxed{2000}$$

✅ Correct Answer: B. $2,000

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