Final answer:
The average distance between the orbits of Mercury and Venus is 0.33 astronomical units.
Step-by-step explanation:
The average distance between the orbits of Mercury and Venus can be calculated by finding the difference between their average orbital distances from the Sun. The average distance from the Sun to Mercury is 0.39 astronomical units (AU), and the average distance from the Sun to Venus is 0.72 AU. So, the average distance between their orbits is:
0.72 AU - 0.39 AU = 0.33 AU
Therefore, the average distance between the orbits of Mercury and Venus is 0.33 astronomical units.