Noun problem has 3 senses
  1. problem, job - a state of difficulty that needs to be resolved; "she and her husband are having problems"; "it is always a job to contact him"; "urban problems such as traffic congestion and smog"
    --1 is a kind of difficulty
    --1 has particulars: race problem; balance-of-payments problem
  2. trouble, problem - a source of difficulty; "one trouble after another delayed the job"; "what's the problem?"
    --2 is a kind of difficulty
    --2 has particulars: can of worms; deep water; growing pains; hydra; matter
  3. problem - a question raised for consideration or solution; "our homework consisted of ten problems to solve"
    --3 is a kind of
    question, head
    --3 has particulars:
     puzzle, puzzler, mystifier, teaser; case; homework problem; riddle, conundrum, enigma, brain-teaser; poser, stumper, toughie, sticker; Gordian knot; crossword puzzle, crossword; koan; word square, acrostic; pons asinorum; rebus