There is a question on naming 12 different things in a kitchen/countries (also easier -- no time limit, no constraint on the first letter).
"The test has a sensitivity of 79 percent and a false positive rate of 5 percent in detecting cognitive impairment from normal subjects." btw, you don't need the perfect score to be considered "normal" by the test.
My only experience was with my mother, who recently passed away from a stroke. She was diagnosed with Alzheimer's in her early 60s.
I have no trouble believing this easy test would be impossibly hard for someone with dementia, even in the early stages. At the beginning, my mom seemed fine to anyone she'd meet, yet would routinely not know what day of the week it was. She'd cover for it by saying things like "since I don't work, every day seems like Saturday". She probably would have failed the test right there.