
Mental Reasoning 1- Series: Practice Set of 30 Questions with Step-by-Step Solutions as in Competitive Exams SSC, BSSC, Bank, Railways
Part A: Number Series (संख्या श्रृंखला)
Q1. 2, 4, 8, 16, ?
Step: Each term ×2
✅ Next term = 32
Answer: 32
Explanation (Hindi): हर संख्या पिछली संख्या का दुगना है।
Q2. 5, 10, 20, 40, ?, 160
Step: Multiply by 2 each time.
✅ Missing term = 80
Explanation (Hindi): प्रत्येक संख्या ×2 हो रही है, इसलिए अगली संख्या 80 होगी।
Q3. 1, 4, 9, 16, 25, ?
Step: These are perfect squares.
✅ Next term = 36 (6²)
Explanation (Hindi): सभी वर्ग संख्या हैं।
Q4. 3, 6, 12, 24, 48, ?
Step: ×2 pattern.
✅ Next = 96
Explanation (Hindi): हर संख्या पिछली का दोगुना है।
Q5. 2, 6, 12, 20, 30,?
Step: Difference = +4, +6, +8, +10 → next +12
✅ Next = 42
Explanation (Hindi): अंतर क्रमशः बढ़ रहा है।
Q6. 1, 3, 6, 10, 15, ?
Step: Differences = +2, +3, +4, +5 → next +6
✅ Next = 21
Explanation (Hindi): यह त्रिभुज संख्याओं की श्रृंखला है।
Q7. 7, 14, 28, 56,?
Step: ×2 pattern.
✅ Next = 112
Explanation (Hindi): हर बार दोगुना।
Q8. 2, 3, 5, 8, 12, 17, ?
Step: Differences = +1, +2, +3, +4, +5 → next +6
✅ Next = 23
Explanation (Hindi): बढ़ते हुए अंतर से श्रृंखला बनी है।
Q9. 2, 6, 18, 54,?
Step: ×3 pattern.
✅ Next = 162
Explanation (Hindi): प्रत्येक पद ×3 किया गया है।
Q10. 1, 2, 6, 24, 120, ?
Step: ×1, ×2, ×3, ×4, ×5 → next ×6
✅ Next = 720
Explanation (Hindi): यह factorial श्रृंखला है।
Part B: Alphabet Series (वर्णमाला श्रृंखला)
Q11. A, C, E, G, ?
Step: +2 letters
✅ Next = I
Explanation (Hindi): हर बार दो अक्षर छोड़कर।
Q12. Z, X, V, T, ?
Step: -2 letters
✅ Next = R
Explanation (Hindi): उलटी दिशा में दो अक्षर कम।
Q13. A, D, H, M, ?
Step: +3, +4, +5 → next +6
✅ Next = S
Explanation (Hindi): बढ़ते हुए अंतर से अक्षर आगे बढ़ते हैं।
Q14. A, Z, B, Y, C, X, ?
Step: Two alternate sequences – A, B, C… and Z, Y, X…
✅ Next = D, W
Explanation (Hindi): अक्षर क्रम दो दिशाओं में चल रहे हैं।
Q15. B, E, H, K, N,?
Step: +3 each time
✅ Next = Q
Explanation (Hindi): हर बार तीन अक्षर छोड़े जा रहे हैं।
Part C: Alphanumeric Series (अक्षर–संख्या मिश्रित श्रृंखला)
Q16. A1, B2, C3, D4, ?
Step: Letter +1, Number +1
✅ Next = E5
Q17. A2, C4, E6, G8, ?
Step: Letters +2, Numbers +2
✅ Next = I10
Q18. 1A, 2B, 4C, 8D, ?
Step: Numbers ×2, Letters +1
✅ Next = 16E
Q19. B1, D4, F9, H16, ?
Step: Letters +2, Numbers are squares (1,4,9,16,25)
✅ Next = J25
Q20. Z9, Y8, X7, W6, ?
Step: Letters -1, Numbers -1
✅ Next = V5
Part D: Mixed Series (Symbols + Letters + Numbers)
Q21. A1$, B2%, C3&, D4#, ?
Pattern: Letters +1, Numbers +1, Symbols alternate
✅ Next = E5@
Q22. Z9#, X8$, V7%, ?
Step: Letters -2, Numbers -1
✅ Next = T6^
Q23. 1A*, 3C*, 5E*, ?
Step: Numbers +2, Letters +2
✅ Next = 7G*
Q24. A2$, C4#, E6%, G8&, ?
Step: +2 in both letters & numbers
✅ Next = I10*
Q25. 2B@, 4D#, 6F$, 8H%, ?
Step: Numbers +2, Letters +2, Symbols alternate
✅ Next = 10J@
Part E: Logical / Figurative Series (Verbal Description)
Q26. Square → Pentagon → Hexagon →?
Step: Increasing sides +1
✅ Next = Heptagon (7 sides)
Q27. Arrow: ↑ → ↓ →?
Step: Rotates 90° clockwise
✅ Next = ←
Q28. Figure with 1 dot → 2 dots → 3 dots →?
✅ Next = 4 dots
Q29. Triangle shaded left → right → top →?
✅ Next = Bottom shaded
Q30. Circle → Half Circle → Quarter Circle →?
✅ Next = One-eighth Circle (1/8)
Summary / Quick Trick Table
Type | Key Clue | Typical Pattern |
Number Series | Differences or ratios | +, ×, squares |
Alphabet Series | Position jumps | +n / -n |
Alphanumeric | Combined | Letter + Number logic |
Mixed | Include symbols | All 3 vary |
Logical | Shapes/directions | Rotation, addition, flip |
To master it, practice regularly.