Group testing

In combinatorial mathematics, group testing refers to any procedure which breaks up the task of locating elements of a set which have certain properties into tests on subsets ("groups") rather than on individual elements. A familiar example of this type of technique is the false coin problem of recreational mathematics. In this problem there are n coins and one of them is false, weighing less than a real coin. The objective is to find the false coin, using a balance scale, in the fewest number of weighings. By repeatedly dividing the coins in half and comparing the two halves, the false coin can be found quickly as it is always in the lighter half.