Final answer:
In the grapefruit model of the solar system, it would take more than just a few minutes to walk from the Sun to the inner edge of the Kuiper Belt (Pluto).
Step-by-step explanation:
In the grapefruit model of the solar system, the distance from the Sun to the inner edge of the Kuiper Belt, where Pluto is located, is represented as 30 blocks in the model. According to the description given, each block represents a distance of about 150 meters. Therefore, to walk from the Sun to the inner edge of the Kuiper Belt, it would take approximately 30 blocks * 150 meters/block = 4500 meters. Since the speed of walking varies from person to person, the time it would take to walk this distance can vary. However, it would likely take more than just a few minutes to cover a distance of 4500 meters on foot.