How should candidates pick the right LRDI sets to attempt during CAT?

Candidates should scan all LRDI sets in the first 2-3 minutes and pick the two most solvable ones based on four quick filters: whether you immediately grasp what the set describes, whether you've solved similar puzzles before, whether questions ask for definite values (easier) or max/min scenarios (harder), and whether solving one question unlocks others in the same set. The two sets that pass all four filters deserve 12-15 minutes each, leaving time for a third attempt if you finish early.

The Four-Filter Scan

Start by reading the first 2-3 lines of each set's instructions. You're not solving yet, just triaging. Set familiarity is the strongest predictor of speed: if you've practiced seating arrangements, blood relations, or tournament formats in mocks, you'll spot patterns faster. Definite-value questions (e.g., "Who sits third from the left?") are almost always quicker than optimization puzzles (e.g., "What is the maximum number of matches Team A could have won?"), which demand exhaustive case-checking.

Check whether the set has interdependent questions.

If Question 1 asks for a fixed constraint and Questions 2-4 build on that answer, solving the first unlocks the rest. Sets where each question stands alone take longer because you're re-reading conditions every time.

On Reddit, we learnt that aspirants who mark interdependent sets first often finish three sets in 40 minutes, while those who pick standalone questions struggle to complete two.

Execution Strategy

Once you've chosen your first set, commit 12 minutes minimum. Partial abandonment after 5 minutes wastes the time you've already invested.

If you're stuck on one question within the set, skip to the next question in that same set rather than jumping to a new puzzle entirely. The context is already loaded in your working memory.

For your second set, apply the same 12-15 minute window. If both sets finish in under 25 minutes combined, scan the remaining sets again.

Sometimes a set that looked hard on first glance becomes clear once you've warmed up. If nothing clicks, use the remaining time to revisit flagged questions or build a CAT prep plan post-exam to analyze which set types you should drill harder.

Common Pitfalls

Avoid the "easiest first" trap. A set with simple language but 6-7 interlocking conditions can consume 20 minutes, while a dense-looking set with clear constraints might take 8. CAT 2023 Slot 1 had a games-and-tournaments set that looked intimidating but solved in under 10 minutes for candidates who'd practiced similar formats. Conversely, a benign-looking seating arrangement with conditional swaps ate up time because every question required re-checking all prior moves.

Never attempt a set just because it appears in a certain position. The exam doesn't order sets by difficulty.

Some years, the hardest set is first; other years, it's last. Your CAT exam pattern + dates page confirms that LRDI has no fixed difficulty curve within the section.