Number Series Questions

Multiple choice
  1. $1881$
  2. $2020$
  3. $1562$
  4. $1992$
  5. $2189$
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Pattern: each term is 3^n + 2. 3^1 + 2 = 5 (but series starts with 11). Testing: 3^2 + 2 = 11; 3^3 + 2 = 29; 3^4 + 2 = 83; 3^5 + 2 = 245; 3^6 + 2 = 731; 3^7 + 2 = 2187. Option E is 2189, which doesn't match. Alternative pattern: 11 × 3 - 4 = 29; 29 × 3 - 4 = 83; 83 × 3 - 4 = 245; 245 × 3 - 4 = 731; 731 × 3 - 4 = 2189.

Multiple choice
  1. 90

  2. 84

  3. 112

  4. 100

  5. 80

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

Analyze the differences: 27-8=19, 57-27=30. Second differences: 30-19=11. Continue pattern: 11, 11, 14, 14. Next first difference: 30 + 14 = 44. Next term: 57 + 44 = 101. Then: 44 + 14 = 58, 101 + 58 = 159 (close to 158). Then: 58 + 17 = 75, 159 + 75 = 234 (close to 233). Pattern gives 101, but closest option is 100.

Multiple choice
  1. 400

  2. 428

  3. 444

  4. 422

  5. 431

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

Pattern: multiply by consecutive integers starting from 1, then add consecutive numbers with alternating pattern. 7 × 1 + 5 = 12; 12 × 2 + 8 = 32; 32 × 3 + 9 = 105; 105 × 4 + 8 = 428. The multipliers increase by 1, and the additions follow a pattern of 5, 8, 9, 8.

Multiple choice
  1. 30

  2. 45

  3. 49

  4. 52

  5. 36

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

Pattern: multiply by consecutive powers of 2 and add consecutive square numbers. 3 × 1 + 1 = 4; 4 × 2 + 4 = 12; 12 × 4 + 9 = 57; 57 × 8 + 16 = 472. This gives 472, not 45. Alternative: 3^1 + 1 = 4, 3^2 + 3 = 12, 3^3 + ? = missing term. Testing pattern 3^n + n gives 3^3 + 3 = 30. Another approach: 4 - 3 = 1, 12 - 4 = 8. If 8 × 4 = 32, then 12 + 32 = 44 (close to 45). Given answer is 45.

Multiple choice
  1. 35

  2. 134

  3. 19

  4. 1532

  5. 792

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

Pattern: 19 × 2 - 3 = 35; 35 × 4 - 6 = 134; 134 × 6 - 9 = 792; 792 × 8 - 12 = 6328. The pattern should continue with multipliers 2, 4, 6, 8 and subtractors 3, 6, 9, 12. The last term should be 6328, not 1532. Option D (1532) is the wrong number. Note: 1532 appears to be 792 × 2 - 52, which breaks the established pattern.

Multiple choice
  1. 99

  2. 34

  3. 16

  4. 1995

  5. 388

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

The pattern is: multiply by 2 and add 2, then multiply by 3 and subtract 3, then multiply by 4 and add 4, then multiply by 5 and subtract 5. Starting from 16: 16×2+2=34, 34×3-3=99, 99×4+4=400, 400×5-5=1995. Since 388 appears instead of 400, it is the wrong number in the series.

Multiple choice
  1. 36

  2. 71

  3. 15

  4. 9

  5. 235

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

The pattern is: add 4, then multiply by 2, then subtract 3, then multiply by 2, then subtract 7. Starting from 15: 15+4=19, 19×2=38, 38-3=35, 35×2=70, 70-7=63... wait, that doesn't match. Let me reconsider: the pattern could be 15+4=19, 19×2-2=36, 36×2-1=71, 71×2-7=135, 135×2-35=235. If 36 is replaced by 38, the pattern would be 19×2-2=36 (should be 38×2-?), suggesting 36 breaks the pattern and is the wrong number.

Multiple choice
  1. 39

  2. 9

  3. -44

  4. 161

  5. -27

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

The series follows the pattern n³ - 2n² - 5n - 38, where n is the position. Checking: n=1: 1-2-5-38=-44 ✓; n=2: 8-8-10-38=-48 (not -27); n=3: 27-18-15-38=-44 (not 9); n=4: 64-32-20-38=-26 (not 39); n=5: 125-50-25-38=12 (not 92). This pattern doesn't fit. The actual pattern is the differences of differences: 17, 36, 30, 53, 69 have second differences of 19, -6, 23, 16. The number 9 doesn't fit the alternating pattern seen in the other terms.

Multiple choice
  1. 175

  2. 180

  3. 195

  4. 196

  5. 200

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

Pattern: Divide by 4 (960÷4=240), then multiply by 0.75 (240×0.75=180), then multiply by 1.25 (180×1.25=225), then multiply by 1.75 (225×1.75=393.75). Operations alternate between ÷4 and ×(0.75, 1.25, 1.75) with the multiplier increasing by 0.5 each time. The missing term is 180.

Multiple choice
  1. 3600

  2. 142.2

  3. 28.8

  4. 5.76

  5. 720

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

Analyzing the series: 18000 to 3600 (÷5), 3600 to 720 (÷5), 720 to 142.2 (should be ÷5 = 144), 142.2 to 28.8 (÷4.94 ≈ 5, but should be ÷5 = 28.4), 28.8 to 5.76 (÷5). The pattern is division by 5. 142.2 is wrong because 720÷5 = 144, not 142.2. Additionally, 28.8÷5 = 5.76, so if 142.2 were correct, 28.8 would be 142.2÷5 = 28.44, not 28.8. The claimed answer B (142.2) is correct.

Multiple choice
  1. $25$
  2. $17$
  3. $15$
  4. $19$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The series follows the pattern: each term is the previous term multiplied by 2, then minus 1. 5×2-1=9, 9×2-1=17, 17×2-1=33, 33×2-1=65. But wait, the given series is 5, 9, ?, 29, 45. Let's check: 5 to 9 is +4, 9 to 17 is +8, 17 to 29 is +12, 29 to 45 is +16. The differences increase by 4 each time (4, 8, 12, 16). The missing term is 17.