What proportion of adults experience mental health problems?

• A. 1
• B. 5
• C. 10
• D. 20

Answer: (B)

Prevalence is the idea here: mental health problems are relatively common among adults. The widely cited figure is that about one in five adults experiences a mental health problem in a given year, which is roughly 20% of the adult population. The best choice reflects that one-in-five proportion, since it conveys that about twenty out of a hundred adults are affected. Other numbers would imply smaller or larger shares that don’t match that common statistic.