Final answer:
The solution to the candle problem requires realizing that the matchbox can be used as a container for tacks and repurposed as a platform for the candle, demonstrating the concept of functional fixedness in psychology.
Step-by-step explanation:
The solution to the "candle problem" involves overcoming functional fixedness, which is the cognitive bias that limits a person to using an object only in the way it is traditionally used. In the experiment conducted by Duncker in 1945, the key to solving the problem was realizing that the matchbox provided can be emptied and used as a container to hold the tacks, which could then be tacked to the wall to serve as a platform for the candle. This classic psychology problem illustrates how thinking outside the box—in this case, literally using the matchbox as something other than its conventional use—can lead to creative problem-solving.