Alligation Calculations (Medial) Flashcards
Define alligation
Alligation is an arithmetical method of solving problems that involves the mixing of a common ingredient when present in different strengths.
Types of alligation
1) Alligation medial
2) Alligation alternate
Alligation medial
used to determine the strength of a common ingredient in a mixture of two or more preparations.
What is the percentage strength (v/v) of alcohol in a mixture of 300 mL of 40% v/v alcohol, 200 mL of 60% v/v alcohol?
48%
What is the percentage of zinc oxide in an ointment prepared by mixing 200g of 10% ointment, 50g of 20% ointment and 100g of 5% ointment?
10%
What is the percentage strength of alcohol in a mixture of 500mL of 40% v/v alcohol, 400mL of 21% v/v alcohol and 100mL of plain water?
28.4%
What is the percentage strength of alcohol in a mixture of 500ml of 45% v/v alcohol, 500ml of 25% v/v alcohol and 1 liter of pure alcohol?
67.5%