65. Health: The directions for a pain reliever recommend that an adult of 60 kg and over take 4 tablets every 4 hours as needed, and an adult who weighs between 40 and 50 kg take only \(2\dfrac{1}{2}\) tablets every 4 hours as needed. Each tablet weighs \(\dfrac{4}{25}\) gram.
(a) If a 72 kg adult takes 4 tablets, how many grams of pain reliever is he or she receiving?
(b) How many grams of pain reliever is the recommended dose for an adult weighing 46 kg?
(a) \(\dfrac{16}{25}\) gram
(b) \(\dfrac{2}{5}\) gram
(a) \(4\times\dfrac{4}{25}=\dfrac{16}{25}\) gram.
(b) Dose = \(2\tfrac{1}{2}=\dfrac{5}{2}\) tablets → grams \(=\dfrac{5}{2}\times\dfrac{4}{25}=\dfrac{20}{50}=\dfrac{2}{5}\).