Why has the following question been determined to be a self-study question which violates self-study policy?

I did not originally ask the question below that was closed, but would appreciate some clarity so I can better understand SE Q&A policies. The generic reason given for closure was that it was off-topic. More specifically, it was stated in comments by whuber that it was a self-study question and was in violation of self-study policies.

Memoryless property: how does $P(X > s + t \mid X > s) = P(X > t), s, t \ge 0$ imply that $F^c(s + t) = F^c(s) F^c(t), s, t \ge 0$?

I am unable to understand why this question was determined to be a self-study question. Please may someone assist me in understanding what features of this question rendered it so, resulting in its closure?