ZE
ZESTEXAM

IBPS RRB PO Simplification & Approximation

Study Material — 4 PYQs (2021–2021) · Concept Notes · Shortcuts

IBPS RRB PO Simplification & Approximation is a frequently tested subtopic — 4 previous year questions from 2021–2021 papers are included below with concept notes, key rules and shortcut tricks.

4 PYQs
2021–2021
12 Practice
MCQs
10 Key Points
to remember
Free
no login needed
Take Free Mock →Full Practice Set
Also for:IBPS POIBPS ClerkSBI POSBI Clerk
PYQs
4
Practice
12
Key Points
10
Access
Free
Previous Year Questions

IBPS RRB PO Simplification & Approximation — Past Exam Questions

4 questions from actual IBPS RRB PO papers · all shown free · click option to reveal solution

Exam Q 12021Previous Year Pattern

If 40% of a number is 240, and 60% of another number is 360, what is the ratio of the first number to the second number?

Exam Q 22021Previous Year Pattern

Simplify: (5⁴ - 5³) ÷ 5² + (3⁵ - 3⁴) ÷ 3³

Exam Q 32021Previous Year Pattern

If (2⁵ × 3⁴ × 5²) ÷ (2³ × 3² × 5) = 2^a × 3^b × 5^c, then find the value of (a + b + c).

Exam Q 42021Previous Year Pattern

A number when divided by 15 leaves remainder 8. The same number when divided by 25 leaves remainder 18. If the number is between 200 and 400, what is the number?

Concept Notes

Simplification & Approximation— Rules & Concept

Core ConceptRead this first — the foundation of the topic
Core Concept

Simplification means solving expressions step by step using BODMAS rule. Approximation means finding values close to exact answers using rounding or estimation techniques. Both skills are essential for solving complex problems in limited exam time

Follow BODMAS strictly

Brackets, Orders (powers/roots), Division, Multiplication, Addition, Subtraction 2. Simplify fractions by finding common factors 3. Convert mixed numbers to improper fractions when needed 4. Use algebraic identities wherever possible Approximation Techniques: 1.

Round numbers to nearest 10, 100, or simple fractions 2. Use estimation for quick elimination of wrong options 3. Apply percentage approximations for decimal calculations

Formula BlockMemorise — at least one formula appears in every paper
• (a + b)² = a² + 2ab + b²
• (a - b)² = a² - 2ab + b²
• a² - b² = (a + b)(a - b)
• (a + b + c)² = a² + b² + c² + 2(ab + bc + ca)
• √(ab) = √a × √b
• Percentage approximation: 0.33 ≈ 1/3, 0.25 = 1/4, 0.125 = 1/8
Exam PatternsWhat examiners ask — read before attempting PYQs

SSC CGL typically asks 3-5 direct simplification questions worth 6-10 marks. Questions involve complex fractions, square roots, percentages, and mixed operations. Time allocation should be maximum 1-2 minutes per question. Powerful Shortcut - Fraction Multiplication Trick: When multiplying fractions, cancel common factors diagonally before multiplying. This reduces calculation time by 50%.

Worked ExampleSolve this step-by-step before moving on
1
Step 1

Convert decimals to fractions = (24/10 × 16/10 × 5/10) / (8/10 × 3/10 × 4/1)

2
Step 2

Simplify by canceling = (24 × 16 × 5) / (10 × 8 × 3 × 4 × 10)

3
Step 3

Cancel common factors 24/8 = 3, 16/4 = 4, 5 cancels with denominator = (3 × 4) / (10 × 3 × 10) = 12/300 = 1/25 = 0.04 Worked Example 2: Approximate: √624 + √1444

1
Step 1

Find perfect squares nearby √624 ≈ √625 = 25 (since 625 = 25²) √1444 ≈ √1444 = 38 (since 38² = 1444)

2
Step 2

Add approximated values 25 + 38 = 63 Exact calculation gives 62.98, so approximation is highly accurate. Mega Shortcut - Options Elimination: In MCQs, approximate the answer first. Eliminate options that are far from your approximation. Then calculate precisely only for remaining close options. The #1 Most Common Trap: Students ignore BODMAS order and calculate left to right. For expression 2 + 3 × 4, wrong approach gives (2 + 3) × 4 = 20. Correct answer following BODMAS: 2 + (3 × 4) = 14. This single mistake can cost 2-4 marks in the exam. Another critical error is incorrect fraction handling. When adding fractions with different denominators, students often add numerators and denominators separately instead of finding LCM first.

Key Points to Remember

  • BODMAS rule is mandatory: Brackets → Orders → Division → Multiplication → Addition → Subtraction
  • Shortcut: (a + b)² = a² + 2ab + b² saves calculation time in complex expressions
  • Approximation formula: Round to nearest easy numbers first, then calculate
  • Fraction multiplication trick: Cancel common factors diagonally before multiplying
  • Time management: Spend maximum 1-2 minutes per simplification question
  • Options elimination: Use approximation to eliminate obviously wrong answers
  • Decimal conversion: 0.25 = 1/4, 0.33 = 1/3, 0.125 = 1/8, 0.2 = 1/5
  • Square root estimation: Memorize perfect squares 1² to 30² for quick approximation
  • Percentage shortcut: 10% of any number = number/10, 1% = number/100
  • Common trap: Never calculate left to right, always follow BODMAS strictly

Exam-Specific Tips

  • Perfect squares to memorize: 25² = 625, 26² = 676, 27² = 729, 28² = 784, 29² = 841, 30² = 900
  • Cube roots: ∛125 = 5, ∛216 = 6, ∛343 = 7, ∛512 = 8, ∛729 = 9, ∛1000 = 10
  • Fraction decimals: 1/7 = 0.142857 (repeating), 1/9 = 0.111... (repeating), 1/11 = 0.090909...
  • Value of √2 = 1.414, √3 = 1.732, √5 = 2.236 for approximation purposes
  • Percentage equivalents: 12.5% = 1/8, 16.67% = 1/6, 37.5% = 3/8, 62.5% = 5/8
  • Powers of 2: 2⁶ = 64, 2⁷ = 128, 2⁸ = 256, 2⁹ = 512, 2¹⁰ = 1024
  • Common algebraic identity: (a + b)³ = a³ + b³ + 3ab(a + b)
  • Simplification weights 8-12% of total Quantitative Aptitude marks in SSC CGL
Practice MCQs

Simplification & Approximation — Practice Questions

12graded MCQs · easy to hard · full solution & trap analysis

All MCQs →
Practice 1easy

What is the approximate value of √625 + ∛216 − 5?

Practice 2easy

Simplify: (48 + 32) ÷ 4 + 12 × 2 − 15

Practice 3easy

What is 15% of 240?

Practice 4easy

What is the value of (7 × 8) − (36 ÷ 6) + 5?

Practice 5easy

Simplify: (144 ÷ 12) × 5 + 18 ÷ 3 − 8

Practice 6easy

Simplify: 256 ÷ 16 + 18 − 12 ÷ 3

Practice 7medium

What is the value of (8³ − 6³) ÷ (8 − 6)?

Practice 8medium

Simplify: (7² + 24²) ÷ 25 + 12 × 3 − 18

Practice 9medium

Simplify: (144 ÷ 12) × 8 + 56 ÷ 7 − 15

Practice 10medium

Approximate: (√196 × √144) ÷ (√64 + √36)

Practice 11medium

Simplify: 15% of 240 + 25% of 160 − 10% of 300

Practice 12medium

What is the approximate value of √(625) + ∛(512) − 2³?

60-Second Revision — Simplification & Approximation

  • Remember: BODMAS rule prevents 80% of calculation errors in simplification
  • Formula: Use (a + b)² = a² + 2ab + b² for quick expansion calculations
  • Trap: Never add fractions by adding numerators and denominators separately
  • Shortcut: Cancel common factors diagonally in fraction multiplication
  • Strategy: Approximate first, eliminate wrong options, then calculate precisely
  • Time-saver: Memorize perfect squares 1² to 30² and cubes 1³ to 10³
  • Key conversion: 0.125 = 1/8, 0.25 = 1/4, 0.33 = 1/3, 0.75 = 3/4
←Fractions & DecimalsBODMAS→
Studied the notes? Now test yourself
See how Simplification & Approximation appears in the real IBPS RRB PO paper
Full timed mock · Instant All-India percentile · Free
Start Free Mock →Practice Panel
✓ Free forever for basic prep✓ No app download✓ Real exam-pattern questions✓ 12,000+ aspirants
Test Simplification & Approximation under exam conditions
Free IBPS RRB PO mock · instant rank · no login
Free Mock →