RRB NTPC Graduate Tier 1

2025

Shift-1

Art and Culture 1

All Questions 1 Architecture 1

Computer Awareness 4

All Questions 4 Hardware 1 Keyboard Shortcuts 1 Software 2

Current Affairs 3

All Questions 3 Appointments 1 Important Days 1 Sports Current Affairs 1

Economy 7

All Questions 7 Banking Current Affairs 1 Current Affairs 3 Government Schemes 1 Important Institutions 1 Indian Economy 1

Environment & Ecology 1

All Questions 1 Current Affairs 1

General Awareness 1

All Questions 1 Indices 1

General Science 4

All Questions 4 Biology 1 Chemistry 2 Physics 1

Geography 5

All Questions 5 Indian Geography 5

History 7

All Questions 7 Ancient History 3 Modern History 4

International Affairs 2

All Questions 2 Current Affairs 2

Mathematics 30

All Questions 30 Algebra 3 Averages 2 Geometry 3 Mensuration 2 Percentages 2 Pipes and Cisterns 1 Problems on Ages 1 Profit and Loss 3 Ratio & Proportion 3 Simple & Compound Interest 2 Simplification 4 Speed, Time and Distance 2 Time and Work 1 Trigonometry 1

Polity 5

All Questions 5 Constitutional Amendments 1 Elections & Political Parties 1 Fundamental Rights 1 Government Schemes 1 Local Government 1

Reasoning 29

All Questions 29 Alphanumeric Series 2 Analogy 3 Blood Relations 1 Classification 3 Coding Decoding 3 Direction Sense 2 Floor Puzzles 1 Mathematical Operations 3 Number Operations 2 Number Series 3 Puzzles 1 Ranking and Order 1 Seating Arrangement 1 Syllogism 1 Venn Diagrams 2

Science & Tech 1

All Questions 1 Space Technology 1

Mathematics

Algebra

EN हिंदी

✕

RRB NTPC Graduate Tier 1 2025 Shift-1 📅 06 May, 2025

If x + (1/x) = 5, then what is the value of x² + (1/x²)?

A

25

B

23

C

27

D

10

Result Summary

APEDIA

RRB NTPC Graduate Tier 1

2025 • 06 May, 2025 • Shift-1

If x + (1/x) = 5, then what is the value of x² + (1/x²)?

Correct Answer

23

Algebraic Identity Selection: The problem necessitates the use of the standard binomial expansion formula: (a + b)² = a² + b² + 2ab.Equation Form......

💡 Analysis & Explanation

Algebraic Identity Selection ▼

The problem necessitates the use of the standard binomial expansion formula: (a + b)² = a² + b² + 2ab.

Equation Formulation ▼

Let 'a' be 'x' and 'b' be '(1/x)'. Squaring both entire sides of the given initial equation yields: (x + 1/x)² = 5².

Expansion and Simplification ▼

Expanding the left side produces x² + (1/x)² + 2(x)(1/x). Since the (x) and (1/x) multiplicatively cancel out to 1, this simplifies precisely to x² + 1/x² + 2 = 25.

Final Deduction ▼

Isolating the target expression by subtracting 2 from both sides gives x² + 1/x² = 25 - 2.

Conclusion ▼

The absolute mathematical value of the expression is 23.