Miscellaneous reasoning for IBPS Clerk

Every reasoning paper has a handful of questions that do not belong to puzzles, seating, syllogism or inequality. They come in ones and twos, the types vary from paper to paper, and most candidates never practise them on purpose. That is a mistake, because they are usually quick. A candidate who has seen each type once can take these marks in 20 seconds each.

This guide covers the types that turn up most in bank clerk papers, each with a method and a worked example. None of them needs new knowledge. They need a habit: write the changed version down before you answer.

Three-digit number sets

A set of five three-digit numbers is given, followed by questions that change the digits in some way and ask which number ends up largest, smallest, and so on.

Example 1. Numbers: 534 · 718 · 296 · 843 · 651

Q1. If the digits of each number are arranged in ascending order, which number becomes the largest?

1. 534 becomes 345; 718 becomes 178; 296 becomes 269; 843 becomes 348; 651 becomes 156.
2. The largest new number is 348.
3. 843.

Q2. If the first and last digits of each number are swapped, which becomes the smallest?

1. 534 becomes 435; 718 becomes 817; 296 becomes 692; 843 becomes 348; 651 becomes 156.
2. 651 (it becomes 156).

Q3. What is the difference between the largest and the smallest original numbers?

1. Largest 843, smallest 296.
2. 843 − 296 = 547.

Q4. What is the sum of the digits of the second-largest number?

1. In order: 843, 718, 651, 534, 296. The second largest is 718.
2. 7 + 1 + 8 = 16.

A trap to watch: the question may ask for the new number or the original number it came from. In Q1, the largest new number is 348, but the answer is the original, 843. Read the last line of the question twice.

Analogies

An analogy gives one pair and asks you to complete a second pair with the same relation. Name the relation in words first, then apply it.

Example 2. ACE : BDF :: GIK : ?

1. A to B, C to D, E to F. Each letter moves +1.
2. G to H, I to J, K to L.
3. HJL.

Odd one out (classification)

Three items share a property and one does not. The trap is that a second property can pick a different item. Before you answer, ask: is there another feature that singles out a different item? If yes, look for the property that only one answer fits.

Example 3. Odd one out: 25, 49, 169, 135.

1. 25 = 5², 49 = 7², 169 = 13². All three are squares.
2. 135 is not a square.
3. Check rivals: all four are odd, and no other feature picks out a single item.
4. 135.

Example 4. Odd one out: BD, FH, JL, NQ.

1. B to D skips one letter (C). F to H skips G. J to L skips K.
2. N to Q skips two letters (O and P).
3. NQ.

Dictionary order

Arrange words as a dictionary would: compare the first letter, and if it matches, the second, and so on. A shorter word that is the start of a longer one comes first.

Example 5. Arrange in dictionary order: Branch, Brain, Bread, Break, Bridge. Which word is third?

1. All start with "Br". Third letters: a, a, e, e, i.
2. Brain and Branch: fourth letters i and n, so Brain comes first.
3. Bread and Break: fifth letters d and k, so Bread comes first.
4. Order: Brain, Branch, Bread, Break, Bridge.
5. Bread.

Symbol substitution

The question swaps the meaning of the operation signs, then asks you to evaluate an expression. Rewrite the expression with the true signs first, then apply the usual order (division and multiplication before addition and subtraction).

Example 6. If + means ÷, − means ×, × means +, and ÷ means −, find 36 + 4 − 3 × 5 ÷ 2.

1. Rewrite: 36 ÷ 4 × 3 + 5 − 2.
2. 36 ÷ 4 = 9, and 9 × 3 = 27.
3. 27 + 5 − 2 = 30.

Logical order

A list of steps or stages is given in jumbled order. Put them in the order they happen. Find the first and last items first. The middle usually falls into place.

Common mistakes

• Answering with the changed number when the question asks for the original, or the reverse.
• In symbol substitution, evaluating before rewriting, then applying the original meanings.
• In odd one out, missing a rival property.
• In dictionary order, comparing only the first letter.

Practice

Aim for six minutes. Questions 1 and 7 use the numbers from Example 1.

1. If 1 is added to the last digit of each number, how many numbers will have all three digits odd?
2. Hand : Glove :: Foot : ?
3. Odd one out: 27, 64, 125, 150.
4. Odd one out: DF, HJ, LN, PS.
5. Which word comes second in dictionary order: Plant, Plane, Planet, Plain, Plate?
6. If × means +, + means −, − means ÷ and ÷ means ×, find 18 × 12 − 4 + 3 ÷ 2.
7. If the second digit of each number is subtracted from the first, which number gives the highest result?
8. Arrange in logical order: (1) Harvest (2) Sowing (3) Ploughing (4) Selling (5) Irrigation.

Answers:

1. Two. The new numbers are 535, 719, 297, 844 and 652. Only 535 and 719 have all odd digits.
2. Sock. Each is worn to cover the part named.
3. 150. The others are cubes (3³, 4³, 5³).
4. PS. The others skip exactly one letter. P to S skips Q and R.
5. Plane. Order: Plain, Plane, Planet, Plant, Plate. Plane is the start of Planet, so it comes first.
6. 15. Rewrite as 18 + 12 ÷ 4 − 3 × 2 = 18 + 3 − 6 = 15.
7. 718. 7 − 1 = 6. The others give 2, −7, 4 and 1.
8. 3, 2, 5, 1, 4. Ploughing, sowing, irrigation, harvest, selling.

What to do next

• Solve one three-digit number set and five mixed questions from this page every day for a week.
• Keep a list of rival properties you have been caught by in odd one out (primes, squares, cubes, palindromes, even and odd).
• Fit these into your sectional plan from the reasoning plan, and see alphabet-based questions for the letter version of these types.