Easy ACT Percentage Practice Questions

Mastering Easy ACT Percentage Practice Questions is a fundamental step for any student aiming to boost their math score on the ACT exam. Percentages appear in various forms on the test, from simple calculations to complex data interpretation and word problems. By understanding the basic relationship between parts and wholes, you can quickly solve a significant portion of the math section. Students preparing for the ACT Prep journey often find that refining these basic skills provides the biggest return on investment for their study time.

Concept Explanation

A percentage is a ratio that expresses a number as a fraction of 100, represented by the symbol "%". In the context of the ACT, percentage problems generally fall into three categories: finding a part of a whole, finding what percent one number is of another, and calculating percentage increases or decreases. The fundamental formula used across these problems is:

$$\ \text{Part} = \ \frac{\ \text{Percent}}{100} \ \times \ \text{Whole}$$

When working with percentages, it is often easiest to convert the percentage into a decimal by moving the decimal point two places to the left. For example, 25% becomes 0.25. To find "25% of 80," you simply multiply $0.25 \ \times 80 = 20$. For percentage change problems, the formula is:

$$\ \text{Percent Change} = \ \frac{\ \text{New Value} - \ \text{Old Value}}{\ \text{Old Value}} \ \times 100$$

Understanding these basics is essential before moving on to more complex topics like ACT Word Problems Practice Questions, where percentages are frequently embedded in real-world scenarios. Many students find that using a calculator is helpful, but recognizing common fractions like $\ \frac{1}{4} = 25\%$ or $\ \frac{1}{3} \approx 33.3\%$ can save valuable seconds during the timed exam. For additional practice with numerical relationships, you might also explore ACT Ratio Practice Questions.

Solved Examples

1. Finding a Part: What is 15% of 120?
   1. Convert the percentage to a decimal: $15\% = 0.15$.
   2. Multiply the decimal by the whole number: $0.15 \ \times 120$.
   3. Calculate the result: $18$.
2. Finding the Percentage: 45 is what percent of 180?
   1. Set up the ratio of part to whole: $\ \frac{45}{180}$.
   2. Simplify the fraction: $\ \frac{45}{180} = \ \frac{1}{4}$.
   3. Convert the fraction to a percentage: $0.25 \ \times 100 = 25\%$.
3. Percentage Increase: A jacket originally cost $80 but is now on sale for $100. What is the percentage increase in price?
   1. Identify the old value ($80) and the new value ($100).
   2. Find the difference: $100 - 80 = 20$.
   3. Divide the difference by the original value: $\ \frac{20}{80} = 0.25$.
   4. Convert to a percentage: $25\%$.

Practice Questions

1. A student answered 24 out of 30 questions correctly on a quiz. What percentage of the questions did the student answer correctly?

2. A local bakery sells 400 loaves of bread a day. If 12% of the loaves are sourdough, how many sourdough loaves are sold each day?

3. If a $60 pair of shoes is discounted by 20%, what is the final sale price of the shoes?

4. A population of a small town increased from 5,000 to 5,500 over one year. What was the percentage increase in the population?

5. 30% of a number is 45. What is the number?

6. In a class of 25 students, 60% are girls. How many boys are in the class?

7. A laptop is priced at $1,200. If a sales tax of 8% is added, what is the total cost of the laptop?

8. A recipe requires 2 cups of sugar. If you decide to reduce the sugar by 25%, how many cups of sugar should you use?

9. A car's value decreased from $20,000 to $16,000. What was the percentage decrease in value?

10. If 40% of $x$ is 20, what is 70% of $x$?

Answers & Explanations

1. 80%. Divide the part by the whole: $\ \frac{24}{30} = 0.8$. Multiply by 100 to get 80%.

2. 48. Multiply the whole by the percentage in decimal form: $400 \ \times 0.12 = 48$.

3. $48. First, find the discount: $0.20 \ \times 60 = 12$. Subtract the discount from the original price: $60 - 12 = 48$. Alternatively, calculate 80% of $60 ($0.80 \ \times 60 = 48$).

4. 10%. Find the increase: $5,500 - 5,000 = 500$. Divide by the original: $\ \frac{500}{5,000} = 0.10$, which is 10%.

5. 150. Set up the equation: $0.30x = 45$. Divide both sides by 0.30: $x = \ \frac{45}{0.30} = 150$.

6. 10 boys. If 60% are girls, then 40% are boys. Calculate 40% of 25: $0.40 \ \times 25 = 10$.

7. $1,296. Find the tax: $0.08 \ \times 1,200 = 96$. Add the tax to the original price: $1,200 + 96 = 1,296$.

8. 1.5 cups. Find the reduction: $0.25 \ \times 2 = 0.5$. Subtract from the original: $2 - 0.5 = 1.5$.

9. 20%. Find the decrease: $20,000 - 16,000 = 4,000$. Divide by the original: $\ \frac{4,000}{20,000} = 0.20$, which is 20%.

10. 35. First, find $x$: $0.40x = 20 \ \rightarrow x = 50$. Then, find 70% of 50: $0.70 \ \times 50 = 35$.

1. What is 40% of 50?

• A10
• B20
• C25
• D30

Frequently Asked Questions

How do I convert a percentage to a decimal?

To convert a percentage to a decimal, remove the percent sign and divide the number by 100, which is equivalent to moving the decimal point two places to the left. For example, 7% becomes 0.07.

What is the difference between percentage point and percent?

A percentage point is the arithmetic difference between two percentages, while percent refers to the relative rate of change. If an interest rate goes from 5% to 6%, it has increased by 1 percentage point, but the percentage increase is actually 20%.

Can a percentage be greater than 100%?

Yes, a percentage can exceed 100% when the part is larger than the original whole, often seen in growth or profit scenarios. For instance, if a company's revenue doubles, it has experienced a 100% increase and is now 200% of its original value.

How do I calculate a percentage on a calculator?

Most calculators allow you to find a percentage by multiplying the whole number by the decimal equivalent of the percentage. Alternatively, some calculators have a dedicated "%" key that automatically handles the division by 100 for you.

What are common percentage mistakes on the ACT?

The most common errors include dividing by the "new" value instead of the "original" value in change problems and forgetting to convert percentages to decimals before multiplying. Always double-check which number represents the "whole" in the context of the question.