(genetics) The observation that the C-value of an organism is not dependent on its complexity (presumed number of genes)

(economics) The paradox raised by a particular (theoretical) lottery game that leads to a random variable with infinite expected value (i.e. infinite expected payoff) but nevertheless seems to be worth only a very small amount to the participants.

An apparent paradox in probability theory, illustrated by various questions about the probability of a child within a family being of a particular sex.

The phenomenon that people can sometimes recover more quickly from more intense emotions or pain than from less distressing experiences, tentatively attributed to the fact that only the more intense states trigger psychological defense processes.

A philosophical problem related to Benardete's paradox, but involving countably many Grim Reapers, each of which will kill the person in question at a certain time (if still alive), taking a certain period of time to do it.

A hypothetical problem dealing with the notion of infinity. Given an empty vase and an infinite supply of balls, an infinite number of steps are performed, such that at each step 10 balls are added to the vase and one ball removed from it. The question is then posed: how many balls are in the vase when the task is finished?

(mathematics) A theorem in set-theoretic geometry, which states that given a solid ball in three‑dimensional space, there exists a decomposition of the ball into a finite number of disjoint subsets, which can then be put back together in a different way to yield two identical copies of the original ball.

The paradox whereby aid agencies report the success of most of their programs, yet it is impossible to establish any significant correlation between aid and GDP growth in developing countries.

A semantic paradox of self-reference, where, supposing that "autological" means "self-describing" and "heterological" means "not self-describing", then "heterological" itself cannot be meaningfully classified as either of the two.

The apparent contradiction that, although water is generally more useful than diamonds, diamonds command a higher price in the market.