think out, reason out, figure out, work outThink out: consider carefully; create or devise by thinkingEg： He wanted to be left alone to think things out.Calm down and think out a solution.The plan was well thought out.Reason out: discover, formulate or conclude by the use of reason; express logically.Eg： He tried hard to reason out the answer to the mystery.The police reasoned out that if the criminal had left by the midday train, it would be easy to pick him up at the terminus.Figure out: understand; determine; ascertain; reason out; discoverEg：I couldnt figure out who he was.He couldnt figure out how it had happened. Im trying to figure out a way to solve the problem.Work out: arrive at by calculation Eg:He worked out the amount of material required.The area can easily be worked out if you know the length and the breadth.Work out also means “solve; find the answer of”He worked out the problem with no difficulty.I havent worked out the algebra problems.Can you work out on the map where we are?