both FALSE

To get zero field at point X, we need a situation where a positive test charge at X would have zero net force on it. This requires the two charges in question to set up equal and opposite contributions to the field at X. This cancellation requires both to repel or both to attract the test charge. In either case, the two charges must have the same sign. The two charges need to have the same magnitude only if X is mid-way along the line joining them. For any other zero-force position along this line, the magnitudes of the two charges need to be different.