Logic puzzles with answers: a practical way to solve them
A logic puzzle gives you a small world and a few true statements. You solve it by writing what each statement rules out, then checking the remaining case against every clue. The answer is the assignment that makes all of the clues true at once.
Published 2026-10-27
Write the cases before you narrate a story
Deduction fails when you hold the whole scene in your head. Put the people, the tasks, or the numbers in a short list and cross off combinations a clue forbids. One clue rarely names the answer. It removes a possibility so the next clue has less room.
When a puzzle says exactly one statement is true, do not look for the cleverest sentence. Test each candidate world. The right world makes exactly one of those sentences true.
Four original puzzles
Open the answer only after you have a full assignment, not a hunch about one name.
Easy
Meera, Arun, and Dev each took one challenge: Sequence, Grid, or Pattern. Meera did not take Sequence. Dev took Grid. The person who took Pattern finished last, and Arun finished before Dev. Who took Sequence?
Answer and reasoning
Answer. Arun took Sequence. Meera took Pattern. Dev took Grid.
Dev is Grid, so Meera is not Sequence and not Grid, which leaves Pattern. Arun is the one left, so Arun took Sequence. Pattern finished last, so Meera is last. Arun before Dev fits the order Arun, Dev, Meera.
Medium
A box holds either 17 or 18. Asha says it is even. Bina says it is greater than 17. Chetan says Asha is wrong. Exactly one of the three statements is true. What is the number?
Answer and reasoning
Answer. 17
If the number is 18, Asha is true and Bina is true, which is two truths. If the number is 17, Asha is false, Bina is false, and Chetan is true. That is exactly one truth.
Medium
Nia, Omar, Priya, and Rohan finish one timed round. Exactly one person finishes between Rohan and Nia. Priya finishes immediately after Rohan. Omar finishes last. What is the order, first to last?
Answer and reasoning
Answer. Rohan, Priya, Nia, Omar.
Omar is last. Priya is immediately after Rohan, so the block is Rohan then Priya. Exactly one person between Rohan and Nia means Nia comes right after Priya. The only order left is Rohan, Priya, Nia, Omar.
Harder
Exactly one of these three statements is true. The code is 13, 14, or 15. (1) The code is 14. (2) The code is even. (3) The code is greater than 14. What is the code?
Answer and reasoning
Answer. 15
13 makes all three statements false. 14 makes both (1) and (2) true. 15 makes only (3) true. The only code with exactly one true statement is 15.
What to do when two cases still fit
If two assignments survive, you missed a clue or you softened one. “Finished before” is an order. “Immediately after” is a neighbour. “Exactly one is true” is a count. Put the words back to their strict meaning and retest.
Logic grids on contest sites often add a points layer and a clock. Puzzle Baron, for example, runs a monthly high-score challenge where difficulty and speed both affect the total. That is a different task from the pencil deduction above: same kind of reasoning, plus a race. Two5’s Logic category is planned around deduction puzzles such as Pattern Breaker, Hidden Rule, and Logic Grid. Those rounds are not open on this website yet.
Sources
On Two5
Prefer a deduction you can score? Logic is one of the two categories Two5 is building first. Friend challenges are not open yet. Join the waitlist if you want a note when early access starts.