alleryStart learning →5 : 24 :: 8 : ?
- 81
- 63
- 48
- 56
Show answer and solution
Correct answer: B. 63
Pattern: n² - 1. 5² - 1 = 24. 8² - 1 = 63.
RRB Group D Odd One Out — practice questions
Explore 22 free Odd One Out questions in RRB Group D Reasoning. Open each question or exercise to read its content, reference answers and available explanation.
Practise Odd One Out with Quill →Odd One Out questions and exercises with answers
Showing questions 1–22 of 22.
5 : 24 :: 8 : ?Read the answer and worked solution →Find the odd one out among the following numbers.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 →
Worked practice questions
Find the odd one out among the following numbers.
- 181
- 169
- 121
- 144
Show answer and solution
Correct answer: A. 181
1. Check each for being a perfect square: 169 = 13², 121 = 11², 144 = 12².
2. For 181, note 13² = 169 and 14² = 196, so 181 is not a perfect square.
3. Therefore 181 is the odd one out.
_Source: RRB Group D (RRC) PYQ, held 27-10-2013, Q.87._
Match each proposition form to its letter
Read exercise and reference answers
- Matching pairs
- Left
- A
- Right
- Universal Affirmative: All S is P
- Left
- E
- Right
- Universal Negative: No S is P
- Left
- I
- Right
- Particular Affirmative: Some S is P
- 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.
How to practise
- Choose a Odd One Out question and try to work out your answer.
- Open the question to check the correct answer and read its worked solution.
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