What is the quickest way to determine the maximum number of sets of cards totally 21 that can be formed from a random half of a deck of cards?
is not formed as a challenge for other programmers to compete on. That means it is off-topic.
However, you should certainly be able to write a challenge from it.
The simplest possibility would be a fastest-code, but a king-of-the-hill where you time the operation of various contestants on a random set of N draws (with
wait4 or the equivalent on non-unix platforms) is another option.
Posing it as a code-golf won't get you screaming fast solutions, but will probably yield some surprising ones.
In any case, to make it a challenge, carefully and unambiguously specify what the entry should do (and if it should be a program or a program fragment) and tell us how entries will be judged.
1 In fact, that suggests one possible a way to formalize fasted-code, which has never had a really precise definition.