How do you calculate the percent increase of a spring that stretches from 12 cm to 15 cm?

To determine the percent increase of the spring that stretches from 12 cm to 15 cm, you use the formula for percent increase, which is:

[ \text{Percent Increase} = \left( \frac{\text{New Length} - \text{Original Length}}{\text{Original Length}} \right) \times 100 ]

In this scenario, the original length of the spring is 12 cm and the new length after stretching is 15 cm.

1. First, calculate the increase in length:

( 15 \text{ cm} - 12 \text{ cm} = 3 \text{ cm} ).

2. Next, plug this increase into the percent increase formula:

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

3. Simplifying this gives:

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

4. Converting that to a percentage results in:

( 0.25 \times 100 = 25% ).

Thus, the correct calculation demonstrates that the percent increase in the