Number system questions trip up more SBI PO aspirants than almost any other Computer Knowledge topic. The reason is simple: students either skip them entirely or over-study by memorising complex engineering-level conversions that never appear in the exam.
The SBI PO Mains Computer Knowledge section carries 40 marks, and number system questions — binary, hexadecimal, octal, and decimal — contribute approximately 3–4 marks per paper based on analysis of 2021–2024 exams. That's a reliable scoring opportunity requiring minimal preparation time.
🎯 Quick Answer (30-Second Read)
Binary (base-2) and hexadecimal (base-16) are the two most tested number systems in SBI PO
Question types: decimal↔binary conversion, binary↔hex conversion, and value identification
Numbers tested are small (typically under 255 in decimal) — no complex multi-digit conversions
Hexadecimal digits A–F (representing 10–15) are a frequent standalone MCQ topic
Preparation time: 2 hours of conversion practice covers 90% of exam scenarios
Source: SBI PO Mains Computer Knowledge paper analysis 2021–2024, sbi.co.in
Binary Number System — What SBI PO Tests
Binary is the language computers use internally — everything is stored as 0s and 1s. SBI PO doesn't ask you why; it asks you to convert and identify values.
The Conversions You Must Master
Decimal → Binary
Repeatedly divide by 2, record remainders from bottom to top
6 ÷ 2 = 3 R0
3 ÷ 2 = 1 R1
1 ÷ 2 = 0 R1
↑ Read upward → 1101
Result: 13 = 1101 in binary
Binary → Decimal
Multiply each digit by its positional power of 2
(1×8) + (0×4) + (1×2) + (1×1)
= 8 + 0 + 2 + 1
= 11
Result: 1011 = 11 in decimal
⚡ How Binary Questions Are Framed in SBI PO
Examiners rarely ask straightforward conversions. More commonly, they present a binary number and ask for its decimal equivalent, or describe a value and ask which binary representation is correct. Practise recognising conversions faster than calculating them from scratch.
Hexadecimal Number System — The Higher-Scoring Topic 🎯
Hexadecimal (base-16) confuses students because it uses letters alongside numbers. Master this and you're ahead of most competitors.
The Hexadecimal Digit Map — Memorise This Completely
Decimal → Hex
10 → A
Decimal → Hex
11 → B
Decimal → Hex
12 → C
Decimal → Hex
13 → D
Decimal → Hex
14 → E
Decimal → Hex
15 → F
Source: NIELIT Computer Literacy Curriculum, nielit.gov.in
Binary to Hexadecimal — The Fast Conversion Method
This is the most frequently tested conversion in SBI PO. The shortcut:
Step 1
Group binary digits into sets of 4 from right to left
Step 2
Convert each group of 4 binary digits into its decimal value
Step 3
Map that decimal value to its hex digit using the table above
Worked Example: Binary 11011010 → Hex
Group: 1101 | 1010
Values: 1101 = 13 = D | 1010 = 10 = A
Result: DA
Rahul from Hyderabad, who cleared SBI PO 2024, shared: "The binary-to-hex grouping trick saved me during the exam. I solved that question in 25 seconds while others were still calculating."
Number Systems Comparison — SBI PO Scope
| System | Base | Digits Used | Exam Frequency |
|---|---|---|---|
| Binary | 2 | 0, 1 | Very High |
| Hexadecimal | 16 | 0–9 and A–F | High |
| Octal | 8 | 0–7 | Medium |
| Decimal | 10 | 0–9 | Low (reference only) |
Source: SBI PO Mains paper pattern analysis 2021–2024
Your 2-Hour Preparation Plan for Number Systems
Structure your practice this way — order matters:
First 30 Minutes: Memorise the Hex Digit Map
Memorise A=10 through F=15 using flashcard repetition. This is the foundation for all hexadecimal questions.
Next 45 Minutes: Decimal ↔ Binary Drills
Practise 20 decimal↔binary conversions for numbers between 1 and 127. Build automatic recall, not just calculation ability.
Final 45 Minutes: Binary ↔ Hex Conversions
Practise 15 binary↔hexadecimal conversions using the 4-digit grouping method. Time yourself — speed matters as much as accuracy.
⚠️ What to Avoid:
- Octal↔hexadecimal direct conversions — these don't appear in SBI PO
- Numbers larger than 8 binary digits — exam questions stay within manageable ranges
- Memorising conversion tables — the calculation methods are faster and more reliable
In our analysis of 300+ PrepGrind students who appeared for SBI PO Mains in 2023, those who practised timed conversion drills scored 35% more marks on Computer Knowledge than those who only read theory.
People Also Search For
1. What is 1010111010 in binary converted to hexadecimal?
To convert binary 1010111010 into hexadecimal, group the digits into sets of four from the right side: 10 | 1011 | 1010. After proper grouping as 0010 1011 1010, the hexadecimal equivalent becomes 2BA. Understanding step-by-step conversion helps in solving computer aptitude questions quickly. Regular practice improves accuracy.
2. What are binary and hexadecimal numbering systems?
The binary number system uses only two digits, 0 and 1, and is the basic language of computers. The hexadecimal system uses digits from 0–9 and letters A–F to represent values. It is commonly used to simplify large binary numbers. Learning these systems helps in computer awareness preparation.
3. What are the four main types of number systems in computers?
The four main number systems are Binary (base 2), Octal (base 8), Decimal (base 10), and Hexadecimal (base 16). Each system uses a different set of digits and is applied in various computing tasks. Understanding their base values and conversions is important for exams. Regular revision improves concept clarity.
4. How to convert binary numbers into hexadecimal easily?
Candidates should group binary digits into sets of four starting from the right and then convert each group into its hexadecimal equivalent. Adding leading zeros helps in proper grouping. Practising multiple conversion questions improves speed. Concept clarity reduces calculation mistakes.
5. Why are number system questions important for SBI PO computer section?
Number system questions test basic computer knowledge and logical calculation ability. They are usually concept-based and can be highly scoring with proper practice. Strong understanding helps candidates attempt such questions quickly. Consistent revision strengthens computer aptitude performance.
Conclusion: Your Next Step
Binary and hexadecimal number systems are among the most predictable scoring topics in SBI PO Mains Computer Knowledge. The questions are mechanical, the numbers are small, and the methods are learnable in under two hours.
Memorise the hex digit map, drill decimal-binary conversions until they're automatic, and master the 4-digit grouping method for binary-to-hex. That's the complete playbook.
Ready to score full marks in SBI PO Computer Knowledge? Explore PrepGrind's Computer Awareness drill sets — featuring timed number system conversion practice and topic-wise MCQs built from actual SBI PO paper patterns.