RMA Medical Mathematics and Dosage Calculations 2 — Questions and Answers
Question 1: An order reads: Infuse 250 mL of NS over 2 hours using a 10 gtt/mL IV set. What is the flow rate in drops per minute?
- 15 gtt/min
- 20 gtt/min
- 21 gtt/min (Correct answer)
- 25 gtt/min
Correct answer: 21 gtt/min
(250 mL × 10 gtt/mL) ÷ (2 hrs × 60 min) = 2,500 ÷ 120 ≈ 21 gtt/min.
Question 2: Convert 37°C to Fahrenheit using the formula F = (C × 9/5) + 32.
- 96.6°F
- 98.6°F (Correct answer)
- 100.4°F
- 102.2°F
Correct answer: 98.6°F
(37 × 9/5) + 32 = 66.6 + 32 = 98.6°F, which is normal body temperature.
Question 3: Which metric prefix represents one-thousandth (0.001) of the base unit?
- Centi-
- Deci-
- Milli- (Correct answer)
- Micro-
Correct answer: Milli-
The prefix milli- denotes 1/1,000 (0.001) of the base unit, as in milligram or milliliter.
Question 4: A patient is ordered 0.4 mg of atropine IM. The vial contains 0.8 mg/mL. How many mL should be administered?
- 0.25 mL
- 0.5 mL (Correct answer)
- 1 mL
- 2 mL
Correct answer: 0.5 mL
(0.4 mg ÷ 0.8 mg/mL) × 1 mL = 0.5 mL.
Question 5: How many teaspoons are equivalent to 1 tablespoon?
- 2 teaspoons
- 3 teaspoons (Correct answer)
- 4 teaspoons
- 5 teaspoons
Correct answer: 3 teaspoons
1 tablespoon equals 3 teaspoons; since 1 teaspoon = 5 mL, 1 tablespoon = 15 mL.
Question 6: A child weighs 44 lbs. Using Clark's Rule (child's weight in lbs ÷ 150 × adult dose), what is the child's dose if the adult dose is 300 mg?
- 44 mg
- 66 mg
- 88 mg (Correct answer)
- 132 mg
Correct answer: 88 mg
(44 ÷ 150) × 300 mg = 0.293 × 300 = 88 mg.
Question 7: In the apothecary system, 1 grain is approximately equivalent to how many milligrams?
- 30 mg
- 60 mg (Correct answer)
- 100 mg
- 120 mg
Correct answer: 60 mg
1 grain (gr) is approximately equal to 60 mg in the standard apothecary-to-metric conversion.
RMA Medical Mathematics and Dosage Calculations 2
An order reads: Infuse 250 mL of NS over 2 hours using a 10 gtt/mL IV set.
What is the flow rate in drops per minute?