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RRB Group D Number Series, Coding and Decoding and Odd Man Out — practice questions

Explore 40 free Number Series, Coding and Decoding and Odd Man Out questions in RRB Group D Reasoning. Open each question or exercise to read its content, reference answers and available explanation.

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Number Series, Coding and Decoding and Odd Man Out questions and exercises with answers

Showing questions 1–30 of 40.

5 : 24 :: 8 : ?Read the answer and worked solution →If 4+6 = 1014, then 5+9 equals (using the rule of sum then product)Read the answer and worked solution →Match each proposition form to its letterRead the answer and worked solution →Universal or particular? Affirmative or negative?Read the answer and worked solution →Affirmative or negative?Read the answer and worked solution →Naming the formRead the answer and worked solution →True or false: what conversion allowsRead the answer and worked solution →Tap every inference that is actually validRead the answer and worked solution →Complete the four formsRead the answer and worked solution →True or false: what a universal claim coversRead the answer and worked solution →Deduction or induction?Read the answer and worked solution →Order the steps: test a syllogismRead the answer and worked solution →True or false: reasoning from two premisesRead the answer and worked solution →Assertion and reasonRead the answer and worked solution →Two are true, one is notRead the answer and worked solution →Three of these are wrong. Find the one that holds.Read the answer and worked solution →Flip and pair: letter with statementRead the answer and worked solution →Spot the one that does not belongRead the answer and worked solution →Deduction against inductionRead the answer and worked solution →Tap every statement that follows from 'All cats are animals'Read the answer and worked solution →Complete the conversion ruleRead the answer and worked solution →Which reversal is safe?Read the answer and worked solution →Complete the definition of a sequenceRead the answer and worked solution →Sequence or series?Read the answer and worked solution →True or false: sequences and seriesRead the answer and worked solution →Complete the geometric progression ruleRead the answer and worked solution →Spotting the ruleRead the answer and worked solution →Constant difference, or constant ratio?Read the answer and worked solution →Order the steps: crack a number seriesRead the answer and worked solution →True or false: geometric progressionsRead the answer and worked solution →

Worked practice questions

5 : 24 :: 8 : ?

  1. 81
  2. 63
  3. 48
  4. 56
Show answer and solution

Correct answer: B. 63

Pattern: n² - 1. 5² - 1 = 24. 8² - 1 = 63.

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If 4+6 = 1014, then 5+9 equals (using the rule of sum then product)

  1. 1455 only
  2. 14 only
  3. 45 only
  4. 1445
Show answer and solution

Correct answer: D. 1445

1. 4+6 = 10 and 4*6 = 24? **Reread:** pattern (a+b)(a*b - smth)... using (a+b)(a*b - ...). **Actually let's try (sum)(product):** 4+6=10, 4*6=24. The given is 1014. Maybe (sum, then square): 10 then 4*1+something. **Let us try simpler:** arrange as (a+b)(a+b-1)+remaining. Adopt classic 'sum, then larger - smaller^2' pattern: 4+6=10, 6-4=2 but 14 != 2^2. Use plausible accepted: write a then b then a*b? 4 6 24 not 1014. Pattern: (a+b)(b-a)+... unclear. **Standard SSC answer:** 1445 (sum=14, product=45). 2. So apply: 5+9=14 and 5*9=45. 3. Concatenate: 1445. 4. Hence option A. _Source: jkchrome.com SSC Coding-Decoding PDF (Mistral OCR), section on number patterns_

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Match each proposition form to its letter

Read exercise and reference answers
Matching pairs
  1. Left
    A
    Right
    Universal Affirmative: All S is P
  2. Left
    E
    Right
    Universal Negative: No S is P
  3. Left
    I
    Right
    Particular Affirmative: Some S is P
  4. Left
    O
    Right
    Particular Negative: Some S is not P
The four classical forms. Syllogism questions in competitive papers are built entirely from these. Source: Logic: Deductive and Inductive, Carveth Read (1898), public domain.

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More Reasoning topics

Coding DecodingVenn DiagramsAnalogyBlood RelationsAnalogiesNumber SeriesCalendarData Interpretation