A document discusses alligation and mixtures, which is the ratio of quantities of items in a mixture. The ratio of the quantity of the first item to the second item is equal to the difference between the cost of the first item and the mean cost, divided by the difference between the cost of the second item and the mean cost. When ingredients of different costs are mixed together, the ratio of their quantities is inversely proportional to the differences between their individual costs and the mean cost of the mixture.

1. ALLIGATION AND
MIXTURES

2. NOTES
• Ratio of the quantity of two items in a mixture
Quantity of 1st item
Quantity of 2nd item
=
C1
C2
Cm
Cm - C2 C1 - Cm
Cm - C2
C1 - Cm
C1 = Cost of item 1
Cm= Mean cost
C2= Cost of item 2
C1 > C2

3. IN OTHER WORDS
• When different quantities of same or different ingredients, of different cost (value)
are mixed together to produce a mixture of a mean cost (value), the ratio of their
quantities are inversely proportional to the differences in their cost from the
mean cost (value)‘
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