The problem asks us to identify which strip model represents 40%. Each strip model is divided into equal parts. We need to determine the fraction of shaded parts for each model and see which one corresponds to 40%.

1. Problem Description

The problem asks us to identify which strip model represents 40%. Each strip model is divided into equal parts. We need to determine the fraction of shaded parts for each model and see which one corresponds to 40%.

2. Solution Steps

Let's analyze each model:

Model 1: There are 5 equal parts, and 2 are shaded. So the fraction is $\frac{2}{5}$. To convert this to a percentage, we can multiply by 100:

$\frac{2}{5} \times 100 = \frac{200}{5} = 40\%$

Model 2: There are 10 equal parts, and 3 are shaded. So the fraction is $\frac{3}{10}$. To convert this to a percentage, we can multiply by 100:

$\frac{3}{10} \times 100 = \frac{300}{10} = 30\%$

Model 3: There are 10 equal parts, and 4 are shaded. So the fraction is $\frac{4}{10}$. To convert this to a percentage, we can multiply by 100:

$\frac{4}{10} \times 100 = \frac{400}{10} = 40\%$

The first and third models represent 40%. However, we are expected to choose only one option. Let us evaluate the description again. It says: "Which model shows 40%?". The models are listed from top to bottom. So we pick the first model.

3. Final Answer

The first model shows 40%.