Number System for SSC CPO | Concepts & Practice | SSC CPO Quantitative Aptitude

Q: How should I revise Number System for SSC CPO?

Revise the core relation, solve one worked example, then attempt a short timed practice set.

Q: Are these official PYQs?

No. Practice questions are labelled from ExamPrepWay's approved original/practice bank unless a verified official source is explicitly shown.

Learn the shortcut

Understand the fastest pattern for this topic before you attempt full MCQs.

Avoid common traps

See where students commonly lose marks so you can eliminate bad options earlier.

Solve faster in exam

Apply one practical method before attempting MCQs and cut down hesitation.

Summary Formula Tricks Mistakes Solved Example Practice FAQ

Number System revision for SSC CPO: understand the base rule, apply the correct formula or relation, check common traps, then practise with approved questions.

Number System covers divisibility, factors, multiples, remainders and properties of integers. SSC questions often reward recognition of divisibility or remainder patterns more than long arithmetic.

SSC CPO focus: Solve the core method first, then use the approved practice questions on this page to build exam-speed accuracy.

Number System revision rule: concept → formula/relation → one worked example → timed practice → error review.

Core concept
Key formula/relation
Common trap
Approved practice

For two positive integers: HCF × LCM = product, when used for the same two numbers
Dividend = Divisor × Quotient + Remainder
0 ≤ remainder < divisor

Use divisibility rules and cyclic remainder patterns before attempting full multiplication or division.

Next Step

Ready to practice this topic?

Solve topic-wise questions, measure accuracy, identify weak areas, and prepare for mock tests faster with a sharper revision flow.

Topic-wise practice built around this concept
Accuracy-focused repetition before full mocks
Weak-area clarity for smarter revision
Faster transition into timed tests

Practice Questions Login for free progress tracking

Free now

You can start learning here right away, explore formulas and tricks, and use the current limited practice flow before premium tools arrive.

Read the exact requirement before choosing a shortcut.
Keep units, signs and percentage bases consistent.
Use the final few seconds to verify direction and magnitude.

Using a memorised shortcut without checking its condition.
Skipping unit or base conversion.
Doing long arithmetic before identifying the underlying relation.

Practice example: What is the least positive number divisible by 8, 12 and 18?

Solution: The least number is 72.

What is the smallest number that must be added to 9876 to make it divisible by 11?
What is the greatest number that divides 187 and 233 leaving remainder 7 in each case?
In a Number System practice set, a student answers 18 questions correctly out of 24. What percentage is correct?

Learn the shortcut first

Shortcut before you solve

Number system questions often hide an easy divisibility shortcut.

Faster solving steps

Use this 4-step method before solving to keep your thinking fast and repeatable.

Step 1 Identify relation

Spot the pattern, relationship, or core idea first.

Step 2 Apply same pattern

Use the same rule instead of re-solving from scratch.

Step 3 Eliminate wrong options

Remove confusing choices before comparing the last few.

Step 4 Confirm final answer

Pick the option that matches the shortcut most cleanly.

Practice Questions

Start with the first 10 questions free, then unlock the rest with premium

Now apply the trick on real questions

Use the shortcut above before solving these questions

Check divisibility rules and parity before doing full calculations.

Tip: A number divisible by 3 has digit sum divisible by 3. A number divisible by 9 has digit sum divisible by 9.

Step 1

Add the digits: 2 + 3 + 4 = 9.

Step 2

Since 9 is divisible by 3, 234 is divisible by 3.

Rule

Use the matching divisibility rule before long division.

3-second trick

For 3 and 9, check the digit sum before anything else.

Trap to avoid

Doing full division when a digit rule gives the answer immediately.

Correct answer

Yes

Thinking path

Digit sum is 9.
9 is divisible by 3.
So 234 is divisible by 3.

Final answer: Yes

Why this is fast: Digit-sum tests save time and reduce arithmetic work.

Free now: first 10 questions Premium later: full solutions, advanced tricks, targeted practice

Q1 Medium

What is the greatest number that divides 187 and 233 leaving remainder 7 in each case?