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About Logical Reasoning — Class 8 Olympiad

Solve analogy, classification, coding-decoding, number series, figure patterns, direction sense, Venn diagrams, mirror images, and paper folding problems. This topic is part of the Olympiad Class 8 mathematics syllabus (chapter: Module 14). On this page you can practice 51 questions across three difficulty levels — 20 easy, 11 medium, and 20 hard — each with a visual step-by-step solution, plus a timed 29-question mastery test with a live leaderboard. Worked examples and sample questions from the topic are below.

Logical Reasoning — solved examples for Class 8 Olympiad

Example 1easy

If 13 : 170 :: 17 : ?
  1. A)290
  2. B)256
  3. C)289
  4. D)325

Step-by-step solution

  1. For the first pair, 13 and 170: 13² = 169. Adding 1 to this gives 169 + 1 = 170.
  2. So the pattern is (Number)² + 1.
  3. Applying this pattern to 17: 17² = 289.
  4. Adding 1 to 289 gives 289 + 1 = 290.

Answer: 290

Example 2medium

Six friends A, B, C, D, E, F are sitting in a circle facing the center. B is between F and C. A is between E and D. F is to the left of D. Who is between A and F?
  1. A)B
  2. B)C
  3. C)D
  4. D)E

Step-by-step solution

  1. 1. Start with 'B is between F and C'. We can represent this as F - B - C or C - B - F in the circle.
  2. 2. Next, 'A is between E and D'. This gives E - A - D or D - A - E.
  3. 3. Now, 'F is to the left of D'. Since everyone is facing the center, 'left' means counter-clockwise. So, the order is D, then F in counter-clockwise direction.
  4. Let's combine these pieces of information. We have two groups: (F, B, C) and (E, A, D). We also know D ... F (counter-clockwise).
  5. From (F - B - C) and (F is to the left of D), we can infer a sequence. If D is at a position, F must be at its left. So, D, then F. Since B is between F and C, the sequence becomes D, F, B, C. (Clockwise: C, B, F, D)
  6. Now, let's incorporate (A is between E and D). We have D as a common point. So, the complete sequence (clockwise) around the circle would be C, B, F, D, E, A. (Counter-clockwise: A, E, D, F, B, C).
  7. Let's verify all conditions with the clockwise arrangement: C, B, F, D, E, A.
  8. - B is between F and C? Yes, (C, B, F).
  9. - A is between E and D? Yes, (D, E, A).
  10. - F is to the left of D? Yes, if facing center, D's left is F.
  11. The arrangement is consistent.
  12. 4. The question asks: Who is between A and F?
  13. Looking at the arrangement (C, B, F, D, E, A), we can see that D and E are between A and F if we go clockwise (F -> D -> E -> A). If we go counter-clockwise (A -> E -> D -> F).
  14. Let's draw the circle: A --- E --- D --- F --- B --- C --- A. Starting from A clockwise: A, then C, B, F, D, E. So F is C, B. Or from A counter-clockwise: A, E, D, F, B, C.
  15. The question 'who is between A and F' implies the direct neighbor in one direction. From our derived order (C, B, F, D, E, A), F and A are separated by D and E in one direction, and by C and B in the other. This usually means the person directly adjacent to both on one side.
  16. Let's draw it:
    A
    E C
    D B
    F

    Starting from D (left of F): D -> F -> B -> C. Then A is between E and D. So, D has E to its right (clockwise) and A to E's right. So, D -> E -> A. This links up: D -> F -> B -> C -> A -> E -> D (clockwise).
  17. Clockwise sequence: D, F, B, C, A, E. (And E is next to D).
  18. Now, who is between A and F? Going clockwise from F, we have B, C, A. Going counter-clockwise from F, we have D, E, A. So D is between A and F when moving counter-clockwise from A towards F.
  19. The clockwise order is: D, E, A, C, B, F. (Connecting F back to D).
  20. Who is between A and F? Going clockwise from A: C, B, F. Going counter-clockwise from A: E, D, F. So, C is between A and F (if we mean the person directly adjacent in a specific direction, usually the shorter path).
  21. Let's re-read 'A is between E and D'. This means E-A-D. 'B is between F and C'. This means F-B-C. 'F is to the left of D'. This means D (clockwise) F. So D is to the right of F. Or D - F (counter-clockwise).
  22. Using D ... F (counter-clockwise):
    _ _ _ D _ _ _ F _ _ _
    E A D (so D is to the right of A, E is to the left of A). E A D. So we have E A D F.

    Now F B C. So E A D F B C.
    Let's check the full circle: E A D F B C. (Clockwise)
    - B is between F and C? Yes. (F-B-C)
    - A is between E and D? Yes. (E-A-D)
    - F is to the left of D? No. D's left is A. D's right is F. So this clockwise order means F is to the right of D. This is incorrect.
  23. Let's restart with 'F is to the left of D' assuming standard counter-clockwise left for facing center. So, if we trace counter-clockwise: D -> F.
    (D, F, _, _, _, _)

    B is between F and C: D, F, B, C.
    (D, F, B, C, _, _)

    A is between E and D: This implies D, E, A (clockwise) or A, E, D (counter-clockwise).
    Since we have D, F, B, C (counter-clockwise), and A is between E and D, the gap is between C and D. So, the sequence clockwise from D must be D, A, E. This means D-A-E (clockwise) is the missing part.
  24. Let's put it together (clockwise): D, A, E, C, B, F. (Connecting F back to D).
    Let's verify:
    1. B is between F and C? (F, D, A, E, C, B) - No. B is between F and C. So F-B-C or C-B-F. In D, A, E, C, B, F, B is between C and F. This works.
  25. 2. A is between E and D? (D, A, E) - Yes.
  26. 3. F is to the left of D? (Clockwise from D is A. Counter-clockwise is F. So yes, F is to the left of D).
  27. So the correct clockwise order is D, A, E, C, B, F.
  28. Now, who is between A and F?
    From A clockwise: E, C, B, F. (E, C, B are between A and F).
    From A counter-clockwise: D, F. (D is between A and F).
  29. The question implies the person directly adjacent to both when traversing the circle. If we follow the sequence D-A-E-C-B-F-D. A is between D and E. F is between B and D. So, if we ask who is between A and F, and we look at the segment D-A-E-C-B-F, we find E, C, B. If we look at the other segment, it's just D.
  30. The question 'who is between A and F' usually implies the one adjacent to both, or the one that completes the shortest segment. In the sequence D, A, E, C, B, F:
  31. A is next to D and E.
  32. F is next to B and D.
  33. The common neighbor for A and F is D. A is right of D, F is left of D. So D is between A and F.

Answer: C

Example 3hard

Identify the number that completes the analogy: 17 : 306 :: 23 : ?
  1. A)506
  2. B)529
  3. C)552
  4. D)576

Step-by-step solution

  1. Analyze the first pair: 17 : 306. We observe that 17 × (17 + 1) = 17 × 18 = 306.
  2. The rule is 'n : n × (n + 1)'.
    nn(n+1)n \rightarrow n(n+1)
  3. Apply the same rule to the second pair: 23 : ?. So, 23 × (23 + 1) = 23 × 24.
  4. Calculate 23 × 24 = 552.

Answer: 552

Practice questions on Logical Reasoning

  1. Q1.easy

    Choose the word which is least like the other words in the group.
    1. A)Emerald
    2. B)Ruby
    3. C)Sapphire
    4. D)Pearl
    Show answer

    Answer: Pearl

    Hint: Consider the origin and classification of each item.

  2. Q2.easy

    If 'FLOWER' is coded as 'GMPXFS', then how is 'GARDEN' coded?
    1. A)HBSDFO
    2. B)HBSEFO
    3. C)HBSDEN
    4. D)HBSEON
    Show answer

    Answer: HBSEFO

    Hint: Observe the consistent shift applied to each letter.

  3. Q3.easy

    What comes next in the sequence: 2, 6, 12, 20, 30, ?
    1. A)38
    2. B)40
    3. C)42
    4. D)44
    Show answer

    Answer: 42

    Hint: Look at the differences between consecutive terms. Do they follow a pattern?

  4. Q4.medium

    Consider the following number series: 3, 7, 16, 35, 74, ?. What is the next number in the sequence?
    1. A)149
    2. B)153
    3. C)157
    4. D)161
    Show answer

    Answer: 153

    Hint: Analyze the differences between consecutive terms. Look for a pattern in these differences.

  5. Q5.medium

    If 'MASTER' is coded as 'QDWXHU', how would 'TRAVEL' be coded using the same logic?
    1. A)XVDZHP
    2. B)YVEZHO
    3. C)WUCYGO
    4. D)XVEZGP
    Show answer

    Answer: XVDZHP

    Hint: Examine the shift in alphabetical position for each letter from 'MASTER' to 'QDWXHU'. Pay attention to whether the letter is a vowel or a consonant.

  6. Q6.medium

    ANALOGY: 123 : 36 :: 234 : 81 :: 345 : ?
    1. A)100
    2. B)121
    3. C)144
    4. D)169
    Show answer

    Answer: 144

    Hint: Look for a mathematical operation involving the digits of the first number that results in the second number.

  7. Q7.hard

    Which number is the odd one out among the following?
    1. A)121
    2. B)289
    3. C)361
    4. D)441
    Show answer

    Answer: 441

    Hint: All numbers are perfect squares. Consider the properties of their square roots.

  8. Q8.hard

    If 'PROBLEM' is coded as 'QSNBMFO', what is the code for 'SOLUTION'?
    1. A)TNNWSF SJ
    2. B)SPMVRFSH
    3. C)TNNYRFSH
    4. D)SPMVWFSJ
    Show answer

    Answer: TNNWSF SJ

    Hint: Examine the shift in each letter of 'PROBLEM' to its corresponding letter in 'QSNBMFO'. The shift might follow a pattern based on the letter's position.

  9. Q9.hard

    Find the next term in the series: 1, 2, 5, 12, 29, ?
    1. A)62
    2. B)70
    3. C)74
    4. D)81
    Show answer

    Answer: 70

    Hint: This is a recursive series. Try to find a relationship between a term and its preceding terms.

These are 9 of the 51 questions available for Logical Reasoning. Start practicing above to unlock visual solutions, AI coaching, and the topic leaderboard — completely free.