NMC CBT NMC-CBT Drug Calculations and Numeracy 2 — Questions and Answers
Question 1: A patient requires 750 micrograms of digoxin. Tablets available are 250 micrograms each. How many tablets should be administered?
- 2 tablets
- 3 tablets (Correct answer)
- 4 tablets
- 1.5 tablets
Correct answer: 3 tablets
750 ÷ 250 = 3 tablets.
Question 2: An IV infusion of 500 mL must run over 4 hours using a standard giving set (20 drops/mL). What is the drip rate in drops per minute?
- 25 drops/min
- 42 drops/min (Correct answer)
- 50 drops/min
- 35 drops/min
Correct answer: 42 drops/min
(500 × 20) ÷ (4 × 60) = 10000 ÷ 240 ≈ 41.7, rounded to 42 drops/min.
Question 3: A child weighing 20 kg requires amoxicillin at 25 mg/kg/day in 3 divided doses. What is the dose per administration?
- 100 mg
- 125 mg
- 150 mg
- 167 mg (Correct answer)
Correct answer: 167 mg
(20 × 25) ÷ 3 = 500 ÷ 3 ≈ 166.7 mg, rounded to 167 mg.
Question 4: Heparin 25,000 units is added to 250 mL of 0.9% saline. The infusion runs at 20 mL/hour. How many units per hour does the patient receive?
- 1,000 units/hr
- 2,000 units/hr (Correct answer)
- 500 units/hr
- 1,500 units/hr
Correct answer: 2,000 units/hr
Concentration = 25,000 ÷ 250 = 100 units/mL; 100 × 20 = 2,000 units/hr.
Question 5: A patient is prescribed morphine 15 mg orally. The syrup available is 10 mg/5 mL. How many mL should be given?
- 5 mL
- 7.5 mL (Correct answer)
- 10 mL
- 12.5 mL
Correct answer: 7.5 mL
(15 ÷ 10) × 5 = 7.5 mL using the formula: required ÷ stock × volume.
Question 6: A nurse needs to prepare a 1:1000 adrenaline solution. What concentration does this represent in mg/mL?
- 0.01 mg/mL
- 0.1 mg/mL
- 1 mg/mL (Correct answer)
- 10 mg/mL
Correct answer: 1 mg/mL
1:1000 means 1 g in 1000 mL = 1000 mg in 1000 mL = 1 mg/mL.
Question 7: A patient's urine output over 8 hours was 360 mL. What is the hourly urine output?
- 30 mL/hr
- 40 mL/hr
- 45 mL/hr (Correct answer)
- 50 mL/hr
Correct answer: 45 mL/hr
360 ÷ 8 = 45 mL/hr.
NMC CBT NMC-CBT Drug Calculations and Numeracy 2
A patient requires 750 micrograms of digoxin.
Tablets available are 250 micrograms each.
How many tablets should be administered?