The problem asks to find the percent increase in the price of a notebook, which rose from $3.30 to $3.80. Here's how to calculate the percentage increase:

Formula for Percent Increase:

$\text{Percent Increase} = \left(\frac{\text{New Price} - \text{Old Price}}{\text{Old Price}}\right) \times 100$

Step 1: Subtract the old price from the new price

$\text{New Price} = 3.80, \quad \text{Old Price} = 3.30$ $\text{Price Increase} = 3.80 - 3.30 = 0.50$

Step 2: Divide the increase by the old price

$\frac{0.50}{3.30} \approx 0.1515$

Step 3: Multiply by 100 to get the percentage

$0.1515 \times 100 = 15.15\%$

Step 4: Round to the nearest tenth

The percent increase is approximately 15.2%.

Would you like more details or have any other questions?

Follow-up questions:

1. What would the percentage change be if the price dropped from $3.80 to $3.30?
2. How do you calculate percentage change if the price fluctuates multiple times?
3. What is the formula for calculating percent decrease, and how does it differ?
4. Can you explain how to round percentages to different decimal places?
5. How do percent increases affect real-life scenarios like inflation?

Tip:

When calculating percent change, always subtract the old value from the new one, regardless of whether the change is an increase or decrease.