A reasonably large percentage of C++ programs written at a particular company compile on the first run, but some do not (a compiler is a program that translates source code, in this case C++ programs, into machine language so programs can be executed).

Suppose an experiment consists of selecting and compiling C++ programs at this location one by one until encountering a program that compiles on the first run.


Denote

  • a program that compiles on the first run by (for success)
  • one that doesn’t do so by (for failure).

Although it may not be very likely, a possible outcome of this experiment is that the first 5 (or 10 or 20 or …) are ‘s and the next one is an . That is, for any positive integer , we may have to examine programs before seeing the first .


The sample space is , which contains an infinite number of possible outcomes.

The same abbreviated form of the sample space is appropriate for an experiment in which, starting at a specified time, the gender of each newborn infant is recorded until the birth of a male is observed.