Finding percentage, rate & base worksheet - Free Printable

Let's solve each problem step by step. The key concept here is understanding the relationship between percentage, rate, and base using the formula:

> Percentage = Rate × Base

Or in equation form:
> $ \text{P} = \frac{R}{100} \times B $

Where:
- P = Percentage (the part)
- R = Rate (the percent, e.g., 10%)
- B = Base (the whole number)

We'll use this to solve each question.

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1. What is 10% of 85?

$$
10\% \text{ of } 85 = \frac{10}{100} \times 85 = 0.1 \times 85 = 8.5
$$

✔ Answer: B. 8.5

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2. 15 is 5% of what number?

Let the unknown number be $ x $.
$$
15 = \frac{5}{100} \times x \\
15 = 0.05x \\
x = \frac{15}{0.05} = 300
$$

✔ Answer: C. 300

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3. What percent of 80 is 4?

Let the percent be $ x $.
$$
\frac{x}{100} \times 80 = 4 \\
0.8x = 4 \\
x = \frac{4}{0.8} = 5
$$

So, 5% of 80 is 4.

✔ Answer: A. 5%

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4. 25% of 50 is what number?

$$
25\% \text{ of } 50 = \frac{25}{100} \times 50 = 0.25 \times 50 = 12.5
$$

✔ Answer: B. 12.5

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5. 25 is 10% of what number?

Let the number be $ x $.
$$
25 = \frac{10}{100} \times x = 0.1x \\
x = \frac{25}{0.1} = 250
$$

✔ Answer: C. 250

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6. 12 is what percent of 30?

Let the percent be $ x $.
$$
\frac{x}{100} \times 30 = 12 \\
0.3x = 12 \\
x = \frac{12}{0.3} = 40
$$

So, 12 is 40% of 30.

✔ Answer: C. 40%

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7. 60% of 90 is what number?

$$
60\% \text{ of } 90 = \frac{60}{100} \times 90 = 0.6 \times 90 = 54
$$

✔ Answer: C. 54

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8. 6 is 12% of what number?

Let the number be $ x $.
$$
6 = \frac{12}{100} \times x = 0.12x \\
x = \frac{6}{0.12} = 50
$$

✔ Answer: B. 50

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9. 70 is what percent of 140?

Let the percent be $ x $.
$$
\frac{x}{100} \times 140 = 70 \\
1.4x = 70 \\
x = \frac{70}{1.4} = 50
$$

So, 70 is 50% of 140.

✔ Answer: C. 50%

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10. 5% of 78 is what number?

$$
5\% \text{ of } 78 = \frac{5}{100} \times 78 = 0.05 \times 78 = 3.9
$$

✔ Answer: B. 3.9

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✔ Final Answers:

1. B. 8.5
2. C. 300
3. A. 5%
4. B. 12.5
5. C. 250
6. C. 40%
7. C. 54
8. B. 50
9. C. 50%
10. B. 3.9

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