Deloitte Logical Reasoning Questions with Worked Answers

Deloitte’s logical reasoning section covers nine question types, from number series to seating arrangements, and runs as a separate timed module within Deloitte India’s campus online assessment.

What the Deloitte Logical Reasoning Section Covers

The logical reasoning module is distinct from the quantitative aptitude and verbal sections. Each is timed independently.

Parameter	Detail
Format	Multiple-choice (MCQ)
Difficulty	Moderate
Position in test	After quantitative aptitude, before verbal
Calculator	Not applicable

The nine question types Deloitte draws from:

• Puzzles and Seating Arrangements
• Data Sufficiency
• Syllogisms
• Objective Reasoning
• Pattern Recognition
• Blood Relations
• Coding Deductive Logic
• Number Series
• Logical Word Sequence

The section-wise syllabus covers how the logical reasoning module sits alongside quantitative aptitude and verbal in the full Deloitte assessment structure.

Sample Questions with Verified Answers

The five examples below span the most frequently tested types. Every solution is re-derived from first principles; none is copied from legacy sources without independent verification.

Pattern Recognition

• Q1: What comes next in the series: 2, 6, 12, 20, 30, ?

• Options: A) 38 B) 40 C) 42 D) 44

• Answer: C) 42

• Solution: Each term equals n × (n+1). Verify: 1×2 = 2, 2×3 = 6, 3×4 = 12, 4×5 = 20, 5×6 = 30, 6×7 = 42. Alternatively, note the differences between consecutive terms: 4, 6, 8, 10 (increasing by 2 each step). The next difference is 12, giving 30 + 12 = 42. Both methods confirm 42.

Blood Relations

• Q2: A man introduces a woman as “the daughter of the only son of my father’s wife.” How is the woman related to the man?

• Options: A) Sister B) Daughter C) Mother D) Niece

• Answer: B) Daughter

• Solution: Parse from the inside out. “My father’s wife” is the man’s mother. “The only son of my mother” is the man himself. “The daughter of the man himself” is his daughter. The woman is his daughter.

Coding Deductive Logic

• Q3: If FLOWER is coded as GMPXFS, how is GARDEN coded?

• Options: A) HBSEFO B) HCTFGO C) IBUEHP D) HBSFEM

• Answer: A) HBSEFO

• Solution: Each letter shifts one position forward in the alphabet. Verify with FLOWER: F→G, L→M, O→P, W→X, E→F, R→S. Apply the same shift to GARDEN: G→H, A→B, R→S, D→E, E→F, N→O. The result is HBSEFO.

Syllogism

• Q4:

  • Statement 1: All doctors are scientists.
  • Statement 2: All scientists are humans.
  • Conclusion: All doctors are humans. Does the conclusion follow?

• Options: A) Conclusion follows B) Conclusion does not follow

• Answer: A) Conclusion follows

• Solution: This is a valid deductive syllogism. If all A are B, and all B are C, then all A are C. Doctors are a subset of scientists; scientists are a subset of humans; therefore doctors are a subset of humans. The conclusion follows necessarily.

Data Sufficiency

• Q5: What is the value of n?

  • Statement 1: 3n + 6 = 21
  • Statement 2: n is a prime number less than 10.

• Options: A) Statement 1 alone is sufficient B) Statement 2 alone is sufficient C) Both statements together are sufficient D) Neither statement is sufficient

• Answer: A) Statement 1 alone is sufficient

• Solution:

  • Statement 1 alone: 3n + 6 = 21 → 3n = 15 → n = 5. This uniquely determines n. Sufficient.
  • Statement 2 alone: n could be 2, 3, 5, or 7. Four possible values. Not sufficient.
  • Statement 1 alone resolves the question. No need to combine statements.

How to Approach Each Question Type

Different logical reasoning types demand different tactics. Apply these by type rather than using one generic strategy.

Pattern Recognition and Number Series

Scan consecutive differences first. If differences are not constant, check whether they form their own arithmetic or geometric sequence. Most Deloitte series follow one of three patterns: arithmetic (constant difference), geometric (constant ratio), or product-based (n×(n+1) style). Identify the pattern in under 20 seconds; if you cannot, skip and return.

Blood Relations

Draw a family tree on rough paper from the outermost reference inward. Never hold the chain in your head. “Father’s wife’s only son” takes four seconds on paper; it takes 30 seconds mental juggling. This type is the highest ROI for time saved.

Coding Deductive Logic

The shift rule covers the largest share of Deloitte coding questions: a fixed offset applied to every letter (each letter +1, each letter -1, or each letter +n). Check the shift value on the first two letters, confirm with the third, then apply uniformly. If the pattern is not a uniform shift, look for alternating shifts (odd positions +1, even positions +2) or positional reversal.

Syllogisms

Use Venn diagrams for any syllogism with three or more terms. Two statements with “All” and “Some” require the diagram to avoid false positives. Write out the set relationship explicitly: A ⊆ B, B ⊆ C → A ⊆ C.

Data Sufficiency

The standard approach: evaluate Statement 1 in isolation. If sufficient, mark A and move on. If not, evaluate Statement 2 in isolation. If sufficient, mark B. If neither alone is sufficient, check whether they work together for C. If not even together, mark D. Never read both statements simultaneously on the first pass.

Preparation Checklist

Ten days of focused work is enough preparation for the logical reasoning section at Deloitte’s moderate difficulty level.

• Days 1 to 3: number series and pattern recognition (fastest return, highest frequency)
• Days 4 to 5: blood relations (tree-drawing method only; no mental chains)
• Days 6 to 7: coding deductive logic (shift patterns and alternating rules)
• Days 8 to 9: syllogisms with Venn diagram practice
• Day 10: data sufficiency with timed mock (aim under 90 seconds per question)

For question variety across all nine types, Deloitte placement papers have full-length logical reasoning sections from previous recruitment cycles.

A consistent resource for pattern recognition and blood relation practice is IndiaBIX’s logical reasoning section, which covers the same question types at comparable difficulty.

Where This Fits in the Full Deloitte Assessment

The logical reasoning module is one of three sections in the Deloitte online test. The quantitative aptitude section covers 14 topics separately, and the verbal section handles reading comprehension, sentence correction, and synonyms. Each section is timed independently, so a weak performance in one does not directly penalise the others.

The scoring threshold for logical reasoning varies by role and recruitment year. Deloitte does not publish cut-offs. Placement cells at colleges that have prior Deloitte recruitment experience are the best source of current-year benchmarks.

The coding deductive logic type in the Deloitte test is a useful proxy for how structured rule-following translates into outcomes. The same mechanic applies when writing instructions for any rule-following system: define the transformation rule precisely, verify it on a known example, apply it uniformly. TinkerLLM is where that instinct meets actual LLM prompting. If the “FLOWER → GMPXFS, what is GARDEN?” format clicked intuitively, prompt engineering will too. TinkerLLM costs ₹499 to start and runs on the same shift-and-verify approach you just practised above.