Use the percent change formula to solve the problem. The price of a book was $12 last year. This year, the price of the book increased to $15. What is the percent increase in the price of the book?

Answer 1

To calculate the percent increase in the price of the book using the percent change formula, you can use the following formula:

\[ \text{Percent Change} = \left( \frac{\text{New Value} - \text{Old Value}}{\text{Old Value}} \right) \times 100 \]

In this case, the old value (last year's price) is $12, and the new value (this year's price) is $15.

1. Calculate the change in value:

\[ \text{Change} = \text{New Value} - \text{Old Value} = 15 - 12 = 3 \]

2. Now, apply the percent change formula:

\[ \text{Percent Increase} = \left( \frac{3}{12} \right) \times 100 \]

3. Calculate the fraction:

\[ \frac{3}{12} = 0.25 \]

4. Now multiply by 100 to get the percentage:

\[ 0.25 \times 100 = 25 \]

Thus, the percent increase in the price of the book is 25%.