Virtual Nodes Load Distribution

A consistent hash ring has 3 servers. Without virtual nodes, a hash function places them at positions 100, 200, and 300 on a ring with range 0–400.

1. What fraction of the key space does each server own?
2. A new "high capacity" server is added at position 350. What fraction of keys does it own? Is this proportional to its "high capacity"?
3. How do virtual nodes solve this problem?