Surds & Indices
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Solved Examples
Study MaterialSolved Examples – Surds & Indices
Solved examples help students understand the practical application of surds, radicals, exponents, and simplification techniques in competitive examinations. These examples are designed from basic to advanced level and cover important questions frequently asked in SSC, Banking, Railway, Insurance, Defence, CAT, CDS, NDA, and various aptitude examinations.
Topics Covered in Solved Examples
- Laws of Indices
- Surd Simplification
- Fractional Powers
- Negative Indices
- Rationalization of Denominators
- Product and Division of Surds
- Radical Transformations
- Advanced Simplification Problems
Example 1: Product Law of Indices
Question: Simplify:
23 × 25
Solution:
Using:
am × an = am+n
23 × 25
= 28
= 256
Answer: 256
Example 2: Division Law of Indices
Question: Simplify:
57 / 53
Solution:
Using:
am / an = am−n
57 / 53
= 54
= 625
Answer: 625
Example 3: Power of a Power
Question: Simplify:
(32)4
Solution:
Using:
(am)n = amn
(32)4
= 38
= 6561
Answer: 6561
Example 4: Zero Index Problem
Question: Simplify:
9990
Solution:
Any non-zero number raised to power zero equals 1.
Therefore:
9990 = 1
Answer: 1
Example 5: Negative Index Problem
Question: Simplify:
2−3
Solution:
Using:
a−n = 1/an
2−3
= 1/23
= 1/8
Answer: 1/8
Example 6: Fractional Power Problem
Question: Simplify:
161/2
Solution:
161/2 = √16
= 4
Answer: 4
Example 7: Simplification of Surds
Question: Simplify:
√72
Solution:
√72 = √(36 × 2)
= √36 × √2
= 6√2
Answer: 6√2
Example 8: Product of Surds
Question: Simplify:
√5 × √20
Solution:
√5 × √20
= √100
= 10
Answer: 10
Example 9: Division of Surds
Question: Simplify:
√50 / √2
Solution:
√50 / √2
= √(50/2)
= √25
= 5
Answer: 5
Example 10: Radical Form Conversion
Question: Express 82/3 in radical form and simplify.
Solution:
82/3 = ∛(82)
= ∛64
= 4
Answer: 4
Example 11: Rationalizing the Denominator
Question: Rationalize:
1/(√3 + 1)
Solution:
Multiply numerator and denominator by:
(√3 − 1)
= (√3 − 1) / [(√3 + 1)(√3 − 1)]
= (√3 − 1)/(3 − 1)
= (√3 − 1)/2
Answer: (√3 − 1)/2
Example 12: Conjugate Surd Problem
Question: Find the conjugate of:
5 + √7
Solution:
Conjugate changes sign between terms.
Therefore:
Conjugate = 5 − √7
Answer: 5 − √7
Example 13: Cube Root Simplification
Question: Simplify:
∛54
Solution:
∛54 = ∛(27 × 2)
= ∛27 × ∛2
= 3∛2
Answer: 3∛2
Example 14: Decimal Root Problem
Question: Simplify:
√0.25
Solution:
√0.25 = √(25/100)
= 5/10
= 1/2
Answer: 1/2
Example 15: Advanced Simplification Problem
Question: Simplify:
(√5 + √3)(√5 − √3)
Solution:
Using identity:
(a + b)(a − b) = a2 − b2
= (√5)2 − (√3)2
= 5 − 3
= 2
Answer: 2
Important Exam Tips
- Memorize all laws of indices thoroughly.
- Learn perfect squares and cubes.
- Practice radical simplification regularly.
- Use conjugates correctly for rationalization.
- Convert fractional powers into radicals quickly.
- Improve simplification speed.
- Practice previous year aptitude questions.
Common Mistakes to Avoid
- Ignoring negative powers.
- Using incorrect surd simplification.
- Forgetting conjugates during rationalization.
- Calculation mistakes in powers.
- Confusing radicals and rational numbers.
Practicing solved examples regularly improves conceptual clarity, calculation speed, and logical analysis in solving Surds & Indices aptitude questions in competitive examinations.