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All coffee mixtures sold in a store contain colombian, [#permalink]
20 May 2006, 17:45
All coffee mixtures sold in a store contain colombian, jamaican or brazilian coffee or some combination of these. Of all mixtures, 33 contain Col, 43 contain Jamaican and 42 contain brazilian. Of these, 16 contain at least col and jamaican, 18 contain at least jamaican and brazilian, 8 contain at least brazilian and colombian and 5 contain all three. how many diffrent coffee mixtures are there?
These problems can be confusion, so you need to read it backwards.
5 contain all three = 5 mixtures
8 contain at least brazilian and colombian = 8-5 = 3 mixtures (because the 5 mixtures above contact brazilian and colombian as well).
18 contain at least jamaican and brazilian = 18-5 = 13 mixtures
16 contain at least col and jamaican = 16-5 = 11 mixtures