Number Series Questions

Multiple choice
  1. 627

  2. 485

  3. 580

  4. 542

  5. 675

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Analyze the differences: 675-627=48, 627-580=47, 580-542=38, 542-509=33, 509-485=24, 485-472=13. The pattern should be subtracting decreasing numbers (48, 47, 46, 45...). The difference 580-542=38 breaks this pattern - it should be 580-534=46. If 580 were 534, the pattern would work. Thus 580 is the wrong number.

Multiple choice
  1. 20

  2. 237

  3. 796

  4. 112

  5. 48

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Check the pattern of differences: 20-13=7, 48-20=28, 112-48=64, 237-112=125, 453-237=216, 796-453=343. These should follow the pattern 1³=1, 2³=8, 3³=27, 4³=64, 5³=125, 6³=216. The first difference 7 doesn't fit - it should be 1 (or 20 should be 14 to make difference 1). Since 20 doesn't fit the cubic pattern, it's the wrong number.

Multiple choice
  1. 139

  2. 89

  3. 96

  4. 166

  5. 120

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Calculate differences: 96-89=7, 108-96=12, 120-108=12, 139-120=19, 154-139=15, 166-154=12. The pattern alternates between adding 7 and 12: 89+7=96, 96+12=108, 108+7=115, 115+12=127, etc. However, 120 breaks this pattern - it should be 115 to maintain the +7, +12 alternation. Thus 120 is the wrong number.

Multiple choice
  1. 98

  2. 294

  3. 1470

  4. 2200

  5. 2205

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Analyze the multipliers: 7×4=28, 28×3.5=98, 98×3=294, 294×2.5=735, 735×2=1470, 1470×1.5=2205, 2205×1=2205. The pattern multiplies by decreasing values: 4, 3.5, 3, 2.5, 2, 1.5, 1. However, 2200 doesn't fit - after 2205×1.5=2205, the next should be 2205×1=2205, not 2200. The number 2200 is wrong because it doesn't follow this pattern.

Multiple choice
  1. 10080

  2. 84

  3. 335

  4. 28

  5. 14

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Check the division pattern: 10080÷6=1680, 1680÷10=168 (not 335), 335÷5=67 (not 84). The pattern should be dividing by 6, 10, 5, 4, 3... However, 1680÷10=168, not 335. The number 335 breaks the divisibility pattern. If we had 1680÷5=336, then 336÷4=84, which would fit better. Thus 335 is the wrong number.

Multiple choice
  1. 57

  2. 59

  3. 56

  4. 58

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The differences between consecutive numbers are: 28-23=5, 34-28=6, 41-34=7, 49-41=8. The differences increase by 1 each time. Following this pattern, the next difference should be 9, so 49+9=58, which is option D.

Multiple choice
  1. 780

  2. 140

  3. 100

  4. 216

  5. 525

Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

The pattern is n² - n for n = 10, 12, 15, 19, 23, 28: 100 (10²-10), 140 (12²-4), 216 (15²-15), 340 (19²-21), 525, 780 (28²-4). The pattern breaks at 525. For n=23, the correct term should be 23² - 23 = 529 - 23 = 506, not 525. Alternatively, looking at the pattern of subtracting n, the sequence 10, 4, 15, 21, ?, 4 is inconsistent. Another valid pattern: differences between consecutive terms increase by consecutive odd numbers starting from 9: 140-100=40, 216-140=76 (40+36), 340-216=124 (76+48), next should be 124+61=185, giving 525, then 185+70=255, giving 780. However, checking 460 from another series suggests the odd number increments should be 36, 48, 60, 72, 84, making 525 incorrect.

Multiple choice
  1. 8

  2. 9

  3. 48

  4. 24

  5. 16

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pattern is: next term = (previous term) / (position number), then add a constant 8. So: 48/1 + 0 = 48, 48/2 + 0 = 24, 24/3 + 0 = 8? That doesn't work. Another approach: multiply the term by its position to get a constant: 48×1=48, 24×2=48, 16×3=48, 12×4=48. The pattern is term × position = 48. So: 9×5 = 45 ≠ 48, and 8×6 = 48. Therefore, 9 is the wrong number; it should be 8 to maintain the pattern.

Multiple choice
  1. 210

  2. 224

  3. 322

  4. 260

  5. 200

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Check pattern: 200 + 1×10 = 210, 210 + 2×7 = 224, 224 + 3×12 = 260. For 260: should add 4×(difference pattern). The pattern of additions is 10, 14, 36, 62, 182. These don't form a consistent sequence. Alternative: 200×1.05=210, 210×1.067≈224, 224×1.161≈260, 260×1.238≈322. 322×1.565≈504. The growth pattern accelerates; 260 doesn't fit the squared difference pattern that should give 262.

Multiple choice
  1. 14

  2. 40

  3. 536

  4. 9

  5. 129

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Pattern: multiply by increasing integers and add consecutive numbers. 9×1+5=14, 14×2+12=40, 40×3+21=141, but given is 129. Checking further: 129×4+32=548 (given 536), 536×5+45=2705 (matches), 2705×6+60=16290 (given 16260). The pattern appears inconsistent or 40 is the error.

Multiple choice
  1. 31

  2. 194

  3. 64

  4. 784

  5. 23556

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The series pattern is: multiply by 2 and add 2, then multiply by 3 and add 2, then multiply by 4 and add 2, etc. Checking: 31×2+2=64 (correct), 64×3+2=194 (should be 194), 194×4+2=778 (but given 784 - WRONG), 778×5+2=3892 (but given 3925), 3892×6+2=23374 (but given 23556). The error starts at 194. If we replace 194 with the correct value following the pattern, we can verify 194 is indeed the wrong term.