There is two clusters of planets: first cluster - planets on distance 10, 20, 30 from Betelgeuse, and second - 50, 60.
If tourist start with any planet from cluster - he can get to any another planet from this cluster, but can't get to any planet from any another cluster.
Every tourist has another restriction: max and min distance to Betelgeuse, so first tourist can visit {10, 20, 30} or {50, 60} in first set only one race, in second set - two races. So answer for first tourist is 2.
Second tourist can visit only {20, 30} - one race - answer is 1.