Explanation:

- Initial Setup: Let's assume the initial length (L) and width (W) of the rectangle. The area is given by Area = L × W.

- Length Increase: The length is increased by 66 2/3%, which is equivalent to multiplying the original length by 5/3. So, the new length is 5L/3.

- Maintain Same Area: To keep the area constant, let the new width be W'. Thus, (5L/3) × W' = L × W.

- Solve for New Width: W' = (L × W) / (5L/3) = 3W/5.

- Width Decrease: The width decreases from W to 3W/5. The percentage decrease is calculated as ((W - 3W/5)/W) × 100% = 2/5 × 100% = 40%.

Correct Option: 3 - 40%