Six statements about a hidden 4-digit code.
Digits are 1–6 and can repeat. Exactly one statement is a lie.
Rule out digits — tap to cross off
Saved on this device
Find the liar. Then find the code.
How to play
A hidden 4-digit code, digits 1 to 6, repeats allowed. You get statements
about it — and exactly one is a lie. Crack it in three attempts, using logic alone.
Three modes, every day. Play any or all of them:
Easy — 3-digit code, 4 statements Medium — 4-digit code, 5 statements Hard — 4-digit code, 6 statements
How to work it out. Take each statement in turn and ask:
if this one is the lie, do the others agree on a single code?
Only one statement survives that test — and the code it leaves is the answer.
1. Position 1 is a 1.
2. The highest digit is 3.
3. The lowest digit is 4.
4. Position 3 is a 2. Statement 3 cannot sit with statement 1 — if position 1 is a 1, the lowest
digit is not 4. So 3 is the lie, the rest are true, and the code is 132.
Stuck? Open the scratchpad. The SCRATCHPAD button under the statements
gives you a notepad and a grid for crossing off digits you have ruled out:
P1123456
P2123456
Everything you write is kept on your device until the next case.
Each guess tells you two things:
▮how many positions are correct
✗how many statements your guess breaks
The right answer breaks exactly one statement — because there is exactly one lie.
Breaking zero means your code is too perfect to be right.