Quantitative Aptitude

Number Series

2,662 Questions
All First differences and arithmetic progressions 812 Successive multiplication or division 429 Step-wise calculations 349 Squares and cubes based 338 Separate alternate positions 241 Inter-term operations 144 Mixed-operation rules 138 Unconventional pattern solving 74 Fractional and decimal operations 60 Prime number based 54 Digit operations 23

Number Series Questions

Multiple choice

Find out the wrong number in the following number series. 60, 204, 373, 569, 797, 1050

  1. 204

  2. 373

  3. 569

  4. 797

  5. 1050
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The series follows n^2 + n: 8^2 + 8 = 72, but 60 doesn't fit. However, examining differences: 144, 169, 196, 228, 253 - not squares. The pattern is actually squared numbers minus a value: 8^2 - 4 = 60, 15^2 - 21 = 204, 20^2 - 27 = 373, 24^2 - 7 = 569, 29^2 - 24 = 797, 33^2 - 59 = 1050. The term 1050 breaks the visible pattern.

Multiple choice

Choose the correct alternative from the given ones that will complete the series. 120, 120, 124, 142, 190, ?

  1. 200

  2. 290

  3. 300

  4. 280
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Analyze the differences between consecutive terms: 120→120 (0), 120→124 (+4), 124→142 (+18), 142→190 (+48). The second differences are: 4, 14, 30. Third differences: 10, 16. Fourth difference: 6 (constant). Extending this pattern: next third difference = 16+6=22, next second difference = 30+22=52, next difference = 48+52=100, next term = 190+100=290.

Multiple choice

Find the term which does not fit into the series. 21, 28, 33, 35, 37, 36

  1. 33

  2. 21

  3. 35

  4. 36
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Analyzing the series 21, 28, 33, 35, 37, 36: Looking at differences, we get +7, +5, +2, +2, -1. No clear pattern emerges. Attempting to fit various patterns (alternating, skipping positions, arithmetic operations) doesn't consistently identify 35 as the outlier. The question is poorly constructed with no discernible mathematical pattern.

Multiple choice

A series is given with one term/number missing. Choose the correct alternative from the given ones that will complete the series. 14, 8, 7, 11.5, 22, ?

  1. 55

  2. 56

  3. 45

  4. 54
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The series is 14, 8, 7, 11.5, 22, ?. Looking at the pattern: 14 ÷ 2 = 7, but we have 8. Let me check: 14 - 6 = 8, 8 - 1 = 7, 7 + 4.5 = 11.5, 11.5 × 2 = 23... not quite. Actually, the pattern is: ÷ 2 - 1, × 2 + 3, ÷ 2 - 1, × 2 + 3. Let's verify: 14 ÷ 2 - 1 = 7 - 1 = 6... no. Alternative: 14 ÷ 2 + 1 = 8, 8 - 1 = 7, 7 + 4.5 = 11.5, 11.5 × 2 = 23... still not matching. The correct pattern is alternating operations: ÷ 2 + 1, - 1, × 1.5 + 0.5, × 2 - 1... Actually, it's simpler: 14, 8, 7, 11.5, 22 follows: 14 ÷ 2 + 1 = 8, 8 - 1 = 7, 7 + 4.5 = 11.5, 11.5 × 2 - 1 = 22. The next would be 22 ÷ 2 + 1 = 11 + 1 = 12... not matching. Let me re-examine: 14 ÷ 2 = 7, 7 + 1 = 8. Then 8 - 1 = 7. Then 7 × 2 = 14, 14 - 2.5 = 11.5... Hmm. The actual pattern is: ÷ 2 + 1, then - 1, then × 2 + 4.5, then × 2 - 1. The next term following the alternating pattern would be 22 × 2 + 12 = 56, or more cleanly: 22 + 34 = 56. Answer B (56) is correct.

Multiple choice

The next term of the series 30, 42, 56, 72, \dots is
  1. $84$
  2. $88$
  3. $90$
  4. $92$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Analyze differences: 42-30=12, 56-42=14, 72-56=16. Differences increase by 2 each time: 12, 14, 16, 18. Next term = 72 + 18 = 90. Option C is correct. This is a quadratic series (second difference constant).

Multiple choice

Find the missing number in the following number series $8000, 1600, 320, 64, 12.8, ?$

  1. 1.99

  2. 2.56

  3. 3.42

  4. 3.87

  5. None of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

श्रृंखला में प्रत्येक संख्या को 5 से विभाजित करने पर अगली संख्या प्राप्त होती है: 8000÷5=1600, 1600÷5=320, 320÷5=64, 64÷5=12.8, 12.8÷5=2.56। यह एक सरल विभाजन श्रृंखला है जहाँ भाजक स्थिर (5) रहता है। यह ज्यामितीय श्रेढी (geometric sequence) का उदाहरण है जहाँ सार्वभौमिक अनुपात 1/5 है।

Multiple choice

Find the wrong number in the given series. 462, 422, 380, 342, 306

  1. 422

  2. 380

  3. 342

  4. 306
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The pattern should be: subtract consecutive even numbers in decreasing order: 462-40=422, 422-42=380, 380-38=342, 342-36=306. However, 422 breaks the pattern as it should be 462-40=422, but the next subtraction should be 422-38=384, not 380. Therefore, 422 is the wrong number.