It's not possible to know the right answers because there never were any. This means the test has no predictive power, not that it's impossible, and again, since some Whites unable to prove education did have to contend with this, it was designed that way intentionally.
I feel "near impossible literacy test" is a terrible description. The "intentionally ambiguous literacy test" would be more apt.
More worrying is I am unable to find a definitive provenance for this document. It suggests it was used in the early 1900s but the print quality and format seems unusual in several ways to me. Which is why I attempted to reduce it in favor of considering the rest of the system.