Real-world examples of sequential percentage changes

📚 Quick Study Guide

• 📈 Percentage Change Formula: Percentage Change = $\frac{\text{New Value - Original Value}}{\text{Original Value}} \times 100$
• 💰 Successive Percentage Changes: When a value is changed by a percentage multiple times, you calculate each change sequentially on the new value obtained after the previous change.
• 🛍️ Discounts: A decrease in price represented as a percentage.
• 🏦 Interest Rates: The percentage charged on the amount you borrow or the return on your investment.
• 👨‍👩‍👧‍👦 Population Growth: The rate at which a population increases (or decreases) over a specific period, expressed as a percentage.
• 📉 Percentage Decrease: Occurs when the new value is lower than the original value, resulting in a negative percentage change.
• 📊 Percentage Increase: Occurs when the new value is higher than the original value, resulting in a positive percentage change.

🧪 Practice Quiz

1. What is the overall percentage change if a stock increases by 10% in the first year and then decreases by 10% in the second year?
   1. A. 0%
   2. B. 1% decrease
   3. C. 1% increase
   4. D. 20% decrease
2. A store offers a 20% discount on a shirt originally priced at $25. Then, they offer an additional 10% off the discounted price. What is the final price of the shirt?
   1. A. $17.50
   2. B. $18.00
   3. C. $20.00
   4. D. $22.50
3. The population of a town increases by 5% in the first year and then decreases by 2% in the second year. What is the net percentage change in population over the two years?
   1. A. 3% increase
   2. B. 3% decrease
   3. C. 2.9% increase
   4. D. 2.9% decrease
4. An item's price increases by 15%, and later decreases by 10%. What is the overall percentage change in the item's price?
   1. A. 5% increase
   2. B. 3.5% increase
   3. C. 6.5% increase
   4. D. 25% increase
5. A company's revenue increases by 25% one year and then decreases by 20% the next year. What is the overall percentage change in revenue?
   1. A. 5% increase
   2. B. 0%
   3. C. 10% increase
   4. D. 45% increase
6. John invests $1000 in a stock. The stock increases by 30% in the first year, then decreases by 20% in the second year. What is the value of his investment after two years?
   1. A. $1040
   2. B. $1100
   3. C. $1000
   4. D. $100
7. A computer's processing speed increases by 50%, but then a software update slows it down by 20%. What is the effective percentage increase in processing speed?
   1. A. 30%
   2. B. 20%
   3. C. 40%
   4. D. 25%