UCAT Logic Puzzles: Constraint Builder
Construct arrangements that satisfy logical rules and inspect every constraint.
Written and reviewed by Dr Akash Gandhi, NHS GP (GMC 7601216) and founder of TheUKCATPeople, teaching the UCAT since 2012. Last reviewed .
Frequently asked questions
What does the UCAT DM Constraint Builder practise?
It practises the ordering and arrangement puzzles in UCAT Decision Making. Instead of choosing from prepared answers, you build an arrangement yourself by placing each item in a slot, which trains you to manage several rules at once.
How does the Constraint Builder work?
Select an item, then choose a slot to place it. A rule checker shows each rule as met, broken or not yet decided as you build. When every slot is filled, check your arrangement. Any arrangement that satisfies every rule is accepted, so there is often more than one correct solution.
How is the Constraint Builder scored?
Each drill has six puzzles and each puzzle is worth one point. You earn the point when your first checked arrangement satisfies every rule. If it breaks a rule, the trainer shows one valid arrangement and you can reset and try again for practice, but no point is awarded for that puzzle.
What happens when I get a puzzle wrong?
You can record the main cause, such as misreading a rule or rushing. Any puzzle you do not solve on your first check is scheduled for review a day later. When puzzles are waiting, a Review mistakes button appears on the results screen and starts a drill of those puzzles, due ones first. To clear a puzzle you need two correct first checks at least three days apart. A correct answer in Review mistakes counts as the first of these even if the puzzle is not yet due, and the second must come at least three days later, so answering twice in one sitting will not clear it. A wrong answer starts the count again.
What is the best strategy for UCAT arrangement puzzles?
Place the most restrictive items first, such as anything fixed to a position or tied to another item. Then use rules that rule positions out to narrow the rest. Watching which rules the checker marks as broken shows you which rule you tend to overlook.
Is my Constraint Builder progress saved?
Yes. Each checked puzzle is saved, and each drill is saved as a session with its score and time, even if you stop part way through. Signed in, it appears on your Dashboard under Decision Making. As a guest it stays on this device until you sign in. Puzzles you do not solve on your first check come back for review, as described below.
How do Constraint Builder puzzles compare with UCAT logical puzzles?
In the real UCAT, logical puzzles are single-answer questions: you choose one of four options for 1 mark. Building the full arrangement yourself, as this trainer asks, is the harder skill, and once it is quick you can often test the four options against the rules instead. Logical puzzles tend to take longer than the 63 second average, so in the exam flag a slow one, make your best guess and come back if time allows.