What problem-solving strategies involve making educated guesses and making efficient use of time?

Actually educated guesses and making use of time efficiently comes from lot of hardwork, discipline, practicing many times and then it’s the pro-activeness and simple use of commonsense to create as many as problem solving strategies and backtest it inorder to win as much as possible and finally good knowledge is very much essential for sure.

The rest don't make sense so i say the first one.

  the correct answer is : binding price ceilings encourage the formation of a black market