Quantitative Aptitudeमात्रात्मक योग्यता · संख्या श्रृंखला

Number Seriesसंख्या श्रृंखला questions and answersप्रश्न और उत्तर

Number series is pattern spotting under time pressure. A fixed checklist of patterns finds most answers in seconds.

Unlimitedअसीमित fresh questionsनए प्रश्न
Answersउत्तर always one tap awayहमेशा एक टैप दूर
1 subtopicउप-टॉपिक
IBPS PO ~5
SSC CGL ~1
TCS NQT ~1

Practice questions are in English for now.अभ्यास के प्रश्न अभी अंग्रेज़ी में हैं।

How number series worksसंख्या श्रृंखला को समझिए

Start with the differences between neighbouring terms. If they don’t settle, take differences again.

If the numbers grow fast, try ratios (×2, ×3, ×1.5) or “× n + k” patterns.

Check squares and cubes (n² ± 1, n³ + n) and series that alternate between two rules.

Tricks that save timeसमय बचाने वाली ट्रिक्स

All tricks →सभी ट्रिक्स →

Each trick says when to use it, why it works and when it fails. Formula tricks are checked by code over their whole range.हर ट्रिक बताती है कि उसे कब इस्तेमाल करें, वह क्यों काम करती है और कब नहीं। सूत्र वाली ट्रिक्स को कोड से उनकी पूरी रेंज पर जाँचा गया है।

Exam strategyपरीक्षा रणनीतिRarely taughtकम सिखाई जाने वाली✓ Checked on 270 cases✓ 270 मामलों पर जाँची गई

The series ladder: six checks in a fixed order

Use it when:कब इस्तेमाल करें: Any number series, missing term, wrong term, or a number analogy or odd-one-out that hides a pattern.

Differences constant? (arithmetic)
Differences of differences constant? (quadratic growth)
Ratios constant? (geometric)
Each term = previous × a + b? Find a from two jumps: a = (t₃ − t₂)/(t₂ − t₁).
Near squares or cubes? Compare with n², n³ and check ± a small constant.
Split odd and even positions: two simpler series interleaved.
Stop at the first check that explains every term, then verify it on the last term too.

Exampleउदाहरण

5, 11, 23, 47, 95, ?

→ Differences 6, 12, 24, 48 → check 4: a = 12/6 = 2, b = 1 → ×2 + 1 → 191

Why it works, and when it failsयह क्यों काम करती है, और कब नहीं

Why:क्यों: Exam setters build series from a handful of rules. Checking them from cheapest to costliest finds the rule with the least arithmetic, and step 4 turns the guess “× something + something” into a calculation.

Limits:सीमाएँ: Rare series mix two operations alternately (×2, +3, ×2, +3). If all six checks fail, try alternating operations on consecutive terms.

Solved examplesहल किए गए उदाहरण

Answers and full solutions are shown. Hide them to test yourself first.उत्तर और पूरे हल दिखाए गए हैं। पहले खुद को परखने के लिए इन्हें छिपाइए।

Example 1उदाहरण 1 · Number series: find the missing term · Easyआसान
Find the missing term: 31, 35, 44, 58, 77, ?
1. 76
2. 81
3. 91
4. 101
Answer:उत्तर: 101
1. Differences: 4, 9, 14, 19, ?.
2. Rule: differences 4, 9, 14, … increase by 5.
3. Missing term = 101.
Example 2उदाहरण 2 · Number series: find the missing term · Mediumमध्यम
Find the missing term: 127, 150, 175, 202, ?, 262
1. 173
2. 185
3. 208
4. 231
Answer:उत्तर: 231
1. Differences: 23, 25, 27, ?, ?.
2. Rule: squares of 11, 12, … + 6.
3. Missing term = 231.
Example 3उदाहरण 3 · Number series: find the missing term · Hardकठिन
Find the missing term: 120, 143, ?, 195, 224, 255
1. 134
2. 168
3. 185
4. 202
Answer:उत्तर: 168
1. Differences: 23, ?, ?, 29, 31.
2. Rule: squares of 11, 12, … − 1.
3. Missing term = 168.
Example 4उदाहरण 4 · Number series: find the missing term · Mediumमध्यम
Find the missing term: 4, ?, 44, 134, 404, 1,214
1. 11
2. 13
3. 14
4. 15
Answer:उत्तर: 14
1. Differences: ?, ?, 90, 270, 810.
2. Rule: each term × 3 + 2.
3. Missing term = 14.
Example 5उदाहरण 5 · Number series: find the missing term · Mediumमध्यम
Find the missing term: 10, 15, 22, ?, 42, 55
1. 23
2. 31
3. 34
4. 37
Answer:उत्तर: 31
1. Differences: 5, 7, ?, ?, 13.
2. Rule: squares of 2, 3, … + 6.
3. Missing term = 31.
Example 6उदाहरण 6 · Number series: find the missing term · Mediumमध्यम
Find the missing term: 7, ?, 23, 34, 47, 62
1. 11
2. 13
3. 14
4. 18
Answer:उत्तर: 14
1. Differences: ?, ?, 11, 13, 15.
2. Rule: squares of 3, 4, … − 2.
3. Missing term = 14.

Common mistakesआम गलतियाँ

Stopping at the first pattern that fits only three terms.
Missing an alternating pattern.

Frequently asked questionsअक्सर पूछे जाने वाले प्रश्न

What is the best approach to number series?

Check differences, then ratios, then squares and cubes, then alternating patterns.

How many number-series questions come in bank prelims?

Often a set of five in IBPS PO and clerk prelims.

Is there a wrong-number format?

Yes. Bank exams also ask you to find the term that breaks the pattern; it is coming to this practice set.