1. 0.5mg=500mcg. 10,000mcg/10ml=1000mcg/ml, so 500mcg in 0.5ml. The amount to be administered is 0.5ml.
2. 50 units/kg requires 50×100=5000 units for a 100kg patient.
20,000 anti Xa IU/2ml=10,000 units/ml and we need half this number of units, so we need 0.5ml.
3. 50mg/5ml=10mg/ml. We need 2mg which is one fifth ml=0.2ml. 0.5ml contains 5mg of the drug.