Unit 9 · Speed and Time Calculation
Six Lunch Boxes — Which Colours Sit at the Ends?
Lesson 6 of 9
About this lesson
Six differently-coloured lunch boxes, three positional clues, and the question: which two boxes sit at each end? This is a classic constraint-satisfaction problem where one powerful clue (purple has only one neighbour) pins down the whole arrangement. Find that anchor clue first and everything else falls into place.
Chapters
Question
There are six lunch boxes lined up on a shelf and each is a different colour: blue, green, orange, purple, red and yellow. There is one box between the green box and the orange box. The purple box's only neighbour is blue, and there are three boxes between the red box and the blue box.
What colour lunch boxes are at each end of the line?
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