Final answer:
Two transformers with a kVA rating of 20 kVA and 10 kVA can handle a combined load of 30 kVA adequately when connected in parallel and properly managed.
Step-by-step explanation:
If two transformers with a kVA rating of 20 kVA and 10 kVA respectively were used to serve a combined load of 30 kVA, the transformers would be utilized to their maximum capacity. The first transformer would be fully loaded at its 20 kVA capacity, while the second transformer would be used at its full 10 kVA capacity.
Together, they can handle the 30 kVA load adequately assuming they are connected properly in parallel and the combined load doesn't exceed the individual transformer's ratings at any time. Transformers in such setups must also share the load in proportion to their ratings to prevent overloading one of the transformers.