Related sobre Yadaim 2:6

If a mikveh was measured and was found lacking [in its prescribed quantity], all things which had been purified in it, whether in private domain or in a public domain, are accounted unclean retroactively. To what does this rule apply? To a serious uncleanness. But in the case of a lesser uncleanness, for instance if he ate unclean foods or drank unclean liquids, or if his head and the greater part of his body entered into drawn water, or if three logs of drawn water fell on his head and the greater part of his body, and he then went down to immerse himself and he is in doubt whether he immersed himself or not, or even if he did immerse himself there is [still] a doubt whether the mikveh contained forty seahs or not, or if there were two mikvehs, one containing forty seahs and not the other, and he immersed himself in one of them but does not know in which of them he immersed himself, in such a doubt he is accounted clean. Rabbi Yose considers him unclean, for Rabbi Yose says: anything which is presumed to be unclean always remains in a condition of unfitness until it is known that it has become clean; but if there is a doubt whether a person became unclean or caused uncleanness, it is to be accounted clean.

Two boxes in two attics, two storage bins in one attic (following Erfurt), behold, these are lifted up. Rabbi Yehuda says, they are not lifeted up. Rabbi Shimon says, even if they are in two cities, one lifts up the terumah of the other (Ter. 4;12). [If there were] one hundred [in one city] and there were not one hundred [in the other city], [he may declare,] "Behold, I say, that inside the one hundred fell one [with the potential to create] a forbidden mixture and one without [the potential to create] a forbidden mixture, behold, I say that inside the forbidden mixture it fell (thus creating a ratio of 101 to 1)."