To solve this problem of finding the percentage decrease, we use the formula for percentage change:

$\text{Percentage Decrease} = \frac{\text{Original Value} - \text{New Value}}{\text{Original Value}} \times 100$

Given:

• Original value (yesterday's price) = 125
• New value (today's price) = 50

Step-by-Step Solution:

1. Find the difference between the original value and the new value: $125 - 50 = 75$

2. Divide the difference by the original value: $\frac{75}{125} = 0.6$

3. Multiply by 100 to convert to a percentage: $0.6 \times 100 = 60\%$

Final Answer:

The percentage decrease is 60%.

Let me know if you need further clarification or details!

Related Questions:

1. How do you calculate percentage increase instead of decrease?
2. If the price drops to $25, what would the percentage decrease be?
3. What is the formula for percentage change, and when is it used?
4. How do you interpret percentage changes in real-life scenarios?
5. If the price increases from $50 to $125, what would the percentage increase be?

Tip:

To check if a percentage change is correct, you can reverse the calculation using the percentage value and the original number to verify.