What's new

Reshuffling cars brainteaser

By David, 13 October 2021 Brainteaser

Difficulty: Extreme!

Illustration of Y shaped street with 6 cars labelled A,A,B,B,C&C. The two A cars are in the lower street but want to be in the street on the left. The two B cars are in the left and want to be right and the two C cars are right and want to be on the lower street.

Terri wants the cars moved around – can you help her do it?

Terri runs a car showroom. It has 3 roads to park cars on, which all meet in the middle of the showroom. Terri can fit 3 cars on each road. If she tries to park a fourth, it blocks the intersection in the middle.

At the moment, there are 2 Audis on one road, 2 BMWs on the second, and 2 Citroëns on the third. Terri wants to move them all around, putting the Audis where the BMWs are, the BMWs where the Citroëns are, and the Citroëns where the Audis are.

Terri isn’t sure she can do it. Can you explain a way to move the cars to the correct location?

Scroll down or click for a hint, or the answer!

brain icon

 

Brainteaser hint

This activity is a lot easier if you make a model. You can draw the roads on a piece of paper and use toy cars or cut up pieces of paper as the cars!

brain icon

 

Brainteaser answer

There are lots of ways to solve the problem, but this method is quite fast:

  1. Illustration of a Y shaped street with Car A moved from lower street to street on the right Start by moving one Audi over to the Citroëns. Eventually it needs to go where the BMWs are, but we need to move the BMWs out of the way first.
  2. Illustration of Y shaped street with both car B's moved from street on the left to lower street Move the 2 BMWs to where the Audis started.
  3. Illustration of Y shaped street with cars A,C&C moved from street on the right to street on the leftMove an Audi and 2 Citroëns into the empty road. That Audi has now reached its goal.
  4. Y shaped street with A, B & B cars moved from lower street to street on the rightMove the BMWs and the other Audi into the empty road. The BMWs are at their goal, and you’ve just made space for the Citroëns.
  5. Illustration of Y shaped street with C&C cars moved from street on the right to lower streetPut the Citroëns on the empty road, which is their goal.
  6. Illustration of Y shaped street with car A moved from street on the right to street on the leftFinally, put the last Audi in its place too!

For more brainteasers and puzzles for kids, subscribe to Double Helix magazine!
 

Subscribe now! button

0 comments

Leave a Reply

By posting a comment you are agreeing to the Double Helix commenting guidelines.

This site uses Akismet to reduce spam. Learn how your comment data is processed.