What problems exist with the Electoral College?

How the electoral college works is that in every state, people vote for a certain candidate. For example, let's say there's Candidate A and Candidate B running for president. If the majority of the state votes for Candidate A, exactly one vote will go towards that candidate. It may seem fair, but it definitely isn't. For another example, let's say that there's State A, State B, and State C. State A has a population of forty million, while State B and State C combined has a population of ten million. State A's majority vote is for Candidate A, but State B and State C's majority vote is Candidate B. Candidate B wins between these three states, since Candidate B has two votes while Candidate A has one vote. So even though State A may have had more votes for Candidate A in numbers, Electoral College allows Candidate B to win, even though the actual numbers are way less than Candidate A's.