Answer
Between $15\space and\space22\space\frac{mg\space acetaminophen}{kg\space body\space weight}$
Work Step by Step
Lower bound: $\frac{1.5\space tsp}{35\space lb\space body\space weight}\times\frac{80\space mg\space acetaminophen}{0.50\space tsp}\times\frac{2.20\space lb}{1\space kg}=15\space\frac{mg\space acetaminophen}{kg\space body\space weight}$
Upper bound: $\frac{1.5\space tsp}{24\space lb\space body\space weight}\times\frac{80\space mg\space acetaminophen}{0.50\space tsp}\times\frac{2.20\space lb}{1\space kg}=22\space\frac{mg\space acetaminophen}{kg\space body\space weight}$
