Simplification
Practice MCQsMathematical simplification involves reducing complex mathematical expressions to simpler forms through various operations such as combining like terms, applying algebraic rules, and removing unnecessary elements. Simplifying mathematical expressions enhances clarity, facilitates problem-solving, and allows for easier manipulation and analysis of mathematical equations and formulas.
Simplification is one of the most frequently asked quantitative aptitude topics. It is based on simplifying numerical expressions using arithmetic operations, brackets, fractions, decimals, percentages, powers, roots, and the correct order of operations. These questions are common in banking exams, SSC, railways, police exams, entrance tests, and other competitive exams.
What is Simplification?
Simplification means reducing a mathematical expression into its simplest possible form. In aptitude exams, simplification questions test speed, accuracy, arithmetic skills, and understanding of operation priority.
Most simplification questions are based on the BODMAS rule. It tells us the correct order in which mathematical operations must be performed.
| Letter | Operation | Meaning |
|---|---|---|
| B | Brackets | Solve expressions inside brackets first |
| O | Order | Powers, roots, squares, cubes |
| D | Division | Perform division before addition/subtraction |
| M | Multiplication | Perform multiplication before addition/subtraction |
| A | Addition | Add numbers after higher priority operations |
| S | Subtraction | Subtract numbers after higher priority operations |
“In simplification, speed comes from knowing operation order and using smart arithmetic.”
Key points
- Always follow BODMAS.
- Solve brackets first.
- Convert mixed fractions if needed.
- Convert percentages into fractions or decimals.
- Use cancellation wherever possible.
- Avoid unnecessary long calculation.
Visual Understanding
These diagrams show how operation order and simplification flow work.
BODMAS Priority Order
Follow this order to avoid mistakes in simplification problems.
Simplification Flow
Division and multiplication are performed before addition and subtraction.
Fraction Simplification
Reduce fractions before performing larger calculations.
Percentage Conversion
Common percentage-to-fraction conversions make simplification faster.
Important Rules and Formulas
BODMAS Rule
Follow this operation order while simplifying.
Fraction Reduction
\(h\) is the HCF of \(a\) and \(b\).
Percentage Form
Convert percentages into fractions or decimals.
Decimal to Fraction
Useful in decimal-based simplification.
Square Rule
Used in order-based simplification.
Square Root
Useful in expressions containing roots.
Reciprocal
Division by a fraction means multiplication by reciprocal.
Mixed Fraction
Convert mixed fractions before calculation.
Common Percentages
Remember common conversions for speed.
More Percentages
Useful for quick mental calculation.
Approximation Check
Used only when approximation is allowed.
Cancellation
Cancel before multiplying to save time.
Common Types of Questions
BODMAS-Based Questions
Expressions containing brackets, division, multiplication, addition, and subtraction.
- Bracket simplification
- Order of operations
- Multiple operators
- Stepwise solving
Fraction Questions
Questions involving addition, subtraction, multiplication, or division of fractions.
- LCM method
- Cancellation
- Mixed fractions
- Reciprocal method
Decimal Questions
Expressions containing decimal numbers and place value operations.
- Decimal addition
- Decimal multiplication
- Decimal division
- Decimal to fraction
Percentage Questions
Convert percentage into fraction or decimal before solving.
- Percentage of number
- Fraction conversion
- Successive percentage
- Fast calculation
Method Bank
Solve brackets before ordinary operations.
Cancel common factors before multiplication.
Convert percentage into fraction.
Convert before calculation.
Tip: In simplification, avoid writing too many steps when cancellation can reduce the expression quickly.
Simplification Solving Flow
Step-by-Step Solving Method
| Step | What to Do | Example |
|---|---|---|
| Step 1 | Read the full expression carefully. | \(18 + 6 \div 3 \times 4\) |
| Step 2 | Solve brackets first, if present. | \((12+8)\div5\) |
| Step 3 | Solve powers and roots. | \(3^2=9\) |
| Step 4 | Perform division and multiplication from left to right. | \(6\div3\times4=8\) |
| Step 5 | Perform addition and subtraction at the end. | \(18+8=26\) |
Solved Examples
| Question | Method | Answer |
|---|---|---|
| Simplify: \(18 + 6 \div 3 \times 4\) |
First solve division and multiplication from left to right.
\[
6 \div 3 \times 4 = 2 \times 4 = 8
\]
\[
18+8=26
\]
|
26 |
| Simplify: \(45 - 5 \times 6 + 12\) |
First multiply.
\[
5\times6=30
\]
Then add/subtract from left to right.
\[
45-30+12=27
\]
|
27 |
| Simplify: \((24+16)\div 5\) |
First solve bracket.
\[
24+16=40
\]
Then divide.
\[
40\div5=8
\]
|
8 |
| Simplify: \(25\%\) of \(240\) |
Convert \(25\%\) into fraction.
\[
25\%=\frac{1}{4}
\]
\[
\frac{1}{4}\times240=60
\]
|
60 |
| Simplify: \(\frac{3}{4}+\frac{1}{2}\) |
Convert to common denominator.
\[
\frac{1}{2}=\frac{2}{4}
\]
\[
\frac{3}{4}+\frac{2}{4}=\frac{5}{4}
\]
|
\(\frac{5}{4}\) |
| Simplify: \(2\frac{1}{2}+3\frac{1}{4}\) |
Convert mixed fractions.
\[
2\frac{1}{2}=\frac{5}{2},\quad 3\frac{1}{4}=\frac{13}{4}
\]
\[
\frac{5}{2}+\frac{13}{4}=\frac{10}{4}+\frac{13}{4}=\frac{23}{4}
\]
|
\(\frac{23}{4}\) or \(5\frac{3}{4}\) |
| Simplify: \(12^2 - 8^2\) |
Calculate squares.
\[
12^2=144,\quad 8^2=64
\]
\[
144-64=80
\]
|
80 |
| Simplify: \(\frac{36\times25}{15}\) |
Cancel before multiplying.
\[
\frac{36\times25}{15}=36\times\frac{5}{3}=12\times5=60
\]
|
60 |
Note: In simplification, a small mistake in operation order can change the entire answer.
Common Traps and Shortcuts
Common Traps
- Solving the expression from left to right without BODMAS.
- Adding before multiplication.
- Ignoring brackets.
- Forgetting to convert mixed fractions.
- Making decimal place mistakes.
- Using approximation when exact answer is required.
Useful Shortcuts
- Cancel common factors before multiplication.
- Convert common percentages into fractions.
- Use squares and cubes from memory.
- Convert decimals into fractions when easier.
- Use LCM for adding fractions.
- Do not skip brackets.
Practice
A) Multiple Choice Questions
-
Simplify: \(20 + 5 \times 4\)
40 100 25 30
-
Simplify: \(36 \div 6 \times 3\)
2 12 18 24
-
\(25\%\) of \(160\) is:
20 30 40 50
-
Simplify: \(\frac{2}{3}+\frac{1}{3}\)
\(\frac{1}{3}\) 1 \(\frac{2}{3}\) 2
-
Simplify: \(9^2 - 7^2\)
22 30 32 34
B) Solve the Higher-Order Problems
- Simplify: \(48 \div 8 \times 6 + 12\) (Hint: Division and multiplication first.)
- Simplify: \((36+24)\div 12 + 15\) (Hint: Solve bracket first.)
- Simplify: \(40\%\) of \(250 + 25\%\) of \(120\) (Hint: Convert percentages to fractions.)
- Simplify: \(\frac{5}{6}+\frac{3}{4}\) (Hint: Use LCM of 6 and 4.)
- Simplify: \(\frac{45\times32}{24}\) (Hint: Cancel before multiplying.)
C) Match the Concept with the Correct Meaning
| Concept | Correct Meaning |
|---|---|
| BODMAS | Correct order of operations |
| Bracket | Solved before other operations |
| Percentage | Number out of 100 |
| Fraction | Part of a whole |
| Cancellation | Removing common factors to simplify calculation |
| Approximation | Using nearby values for quick estimation |
Aptitude Reminder
Simplification questions test accuracy and calculation speed. Always follow BODMAS, simplify fractions, convert percentages, and use cancellation wherever possible.
Task: Create five questions using BODMAS, fractions, percentages, squares, and cancellation.
Show Suggested Answers
Multiple Choice
-
40
Multiplication first:\[ 20+5\times4=20+20=40 \] -
18
Division and multiplication from left to right:\[ 36\div6\times3=6\times3=18 \] -
40
\[ 25\%\text{ of }160=\frac{1}{4}\times160=40 \] -
1
\[ \frac{2}{3}+\frac{1}{3}=\frac{3}{3}=1 \] -
32
\[ 9^2-7^2=81-49=32 \]
Higher-Order Problems
-
Simplify:
\[ 48\div8\times6+12 \]\[ 6\times6+12=36+12=48 \]Answer = 48.
-
First solve bracket:
\[ 36+24=60 \]Then:\[ 60\div12+15=5+15=20 \]Answer = 20.
-
Convert percentages:
\[ 40\%\text{ of }250=\frac{40}{100}\times250=100 \]\[ 25\%\text{ of }120=\frac{1}{4}\times120=30 \]\[ 100+30=130 \]Answer = 130.
-
LCM of 6 and 4 is 12.
\[ \frac{5}{6}+\frac{3}{4} = \frac{10}{12}+\frac{9}{12} = \frac{19}{12} \]Answer = \(\frac{19}{12}\).
-
Simplify by cancellation:
\[ \frac{45\times32}{24} = 45\times\frac{4}{3} = 15\times4 = 60 \]Answer = 60.
Concept Matching
- BODMAS → Correct order of operations
- Bracket → Solved before other operations
- Percentage → Number out of 100
- Fraction → Part of a whole
- Cancellation → Removing common factors to simplify calculation
- Approximation → Using nearby values for quick estimation
Clue Explanation
Simplification becomes easy when you first identify operation priority. Use BODMAS, reduce fractions, convert percentages, and cancel common factors before multiplying.
Exam tips
- Never ignore brackets.
- Apply BODMAS correctly.
- Division and multiplication are solved from left to right.
- Addition and subtraction are solved from left to right.
- Convert percentages into fractions for faster calculation.
- Use cancellation before multiplication.