NMC CBT - Nursing and Midwifery Council Computer-Based Test Drug Calculations and Numeracy 1 — Questions and Answers
Question 1: A patient is prescribed 750 micrograms (mcg) of digoxin orally. The available tablets contain 250 mcg each. How many tablets should be administered?
- 2 tablets
- 3 tablets (Correct answer)
- 4 tablets
- 5 tablets
Correct answer: 3 tablets
Using the formula: dose required ÷ dose available = 750 mcg ÷ 250 mcg = 3 tablets.
Question 2: 500 mL of 5% dextrose is prescribed over 4 hours. The giving set delivers 15 drops per mL. What is the correct drip rate in drops per minute?
- 21 drops/min
- 25 drops/min
- 31 drops/min (Correct answer)
- 42 drops/min
Correct answer: 31 drops/min
Drip rate = (volume in mL × drop factor) ÷ (time in hours × 60) = (500 × 15) ÷ (4 × 60) = 7500 ÷ 240 = 31.25, rounded to 31 drops/min.
Question 3: A child weighing 30 kg is prescribed ibuprofen at 10 mg/kg. The suspension available is 100 mg in 5 mL. What volume should be given?
- 10 mL
- 12 mL
- 15 mL (Correct answer)
- 20 mL
Correct answer: 15 mL
Required dose = 30 kg × 10 mg/kg = 300 mg. Volume = (300 ÷ 100) × 5 = 15 mL.
Question 4: A patient requires a morphine infusion at 2 mg/hour. The available bag contains 50 mg of morphine in 50 mL of 0.9% NaCl. What infusion rate in mL/hr should be set on the pump?
- 1 mL/hr
- 2 mL/hr (Correct answer)
- 4 mL/hr
- 5 mL/hr
Correct answer: 2 mL/hr
Concentration = 50 mg ÷ 50 mL = 1 mg/mL. Infusion rate = 2 mg/hr ÷ 1 mg/mL = 2 mL/hr.
Question 5: A vial contains 1 g of amoxicillin powder. After reconstitution with 10 mL of water for injection, a patient requires 250 mg IV. What volume should be drawn up?
- 1.5 mL
- 2 mL
- 2.5 mL (Correct answer)
- 3 mL
Correct answer: 2.5 mL
Post-reconstitution concentration = 1000 mg ÷ 10 mL = 100 mg/mL. Volume = 250 mg ÷ 100 mg/mL = 2.5 mL.
Question 6: A patient is prescribed a heparin infusion at 1000 units/hour. The infusion bag contains 25,000 units of heparin in 50 mL of 0.9% NaCl. What rate in mL/hr should the pump be set to?
- 1 mL/hr
- 2 mL/hr (Correct answer)
- 4 mL/hr
- 5 mL/hr
Correct answer: 2 mL/hr
Concentration = 25,000 units ÷ 50 mL = 500 units/mL. Infusion rate = 1000 units/hr ÷ 500 units/mL = 2 mL/hr.
A patient is prescribed 750 micrograms (mcg) of digoxin orally.
The available tablets contain 250 mcg each.
How many tablets should be administered?