One-stroke figures
Can one continuous trace cover every line exactly once? Check the connections at each dot.
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Respect the starting point · Find the finish, or recognize when the required start makes a trace impossible.
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6 questions · No time limit
Example
Example
Example · Standard
Start at C. After using every line exactly once, where can you finish?
- Questions answered
- 0 / 6
- Active time
- 0:00
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Choose an answer, then explore a trace and review the connections.
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Reload pageOptional and off by default. Share starts, completions, replays and error categories. For visits from ChatGPT, starts and completions can also include the first QuickenBrain page and broad country. No answers, drawings or names.
How this data is usedHelp
Every labeled dot is a junction. You may revisit a dot, but each line must be used exactly once without lifting your pen. All lines must form one connected group. With no odd connection counts, a trace returns to its start. With exactly two odd counts, it must start and finish at those two dots. Higher levels prescribe a start or ask which extra line makes the required trace possible.
Each round has six questions and no time limit. Choosing an answer locks it. Review the steps, then move to the next question. Finish all six to save the round. Active time includes reviewing the steps, but does not count time when this page is hidden. Speed does not affect your score.
Use Tab and Enter or Space to choose an answer. The number keys also select answers, except when another control is focused. After an answer, Enter goes to the next question.
Original practice puzzles, not a standardized assessment.
About this practice
Learn a method
Trace every edge onceCan one continuous trace cover every line exactly once? Check the connections at each dot.
Report a problem
Optional and off by default. Share starts, completions, replays and error categories. For visits from ChatGPT, starts and completions can also include the first QuickenBrain page and broad country. No answers, drawings or names.
How this data is used