Number Series Questions

Multiple choice
  1. 25

  2. 30

  3. 37

  4. 40

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

The series alternates between adding 7 and adding 5: 6 + 7 = 13, 13 + 5 = 18, 18 + 7 = 25, 25 + 5 = 30, 30 + 7 = 37, 37 + 5 = 42. The number 40 breaks this pattern, as it should be 42 according to the alternating addition rule. This makes 40 the wrong number in the sequence.

Multiple choice
  1. $361:10$
  2. $361:09$
  3. $361:13$
  4. $289:09$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The pattern involves square numbers and operations on their digits. For 256 (√256=16): 1+6=7, 2+5+6=13, difference = 6 or 17-10=7. For 289 (√289=17): 1×7=7. For 324 (√324=18): 1+8=9, 3+2+4=9, difference = 0 or 9-9=0. For 361 (√361=19): the digit product 1×9=9 gives the correct answer. The pattern uses digit operations on the square root, and 361:09 fits.

Multiple choice
  1. 76, 75

  2. 72, 75

  3. 76, 74

  4. 75, 73

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

This is an alternating series. Odd positions: 87, 82, 77, ? (subtract 5 each time). Even positions: 84, 81, 78, ? (subtract 3 each time). Following the odd position pattern: 77-5=72. Following the even position pattern: 78-3=75. The missing terms are 72, 75.

Multiple choice
  1. $36$
  2. $41$
  3. $43$
  4. $54$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The pattern involves adding consecutive squared natural numbers: 13 + 1² = 14, 14 + 2² = 18, 18 + 3² = 27, 27 + 4² = 43, 43 + 5² = 68, 68 + 6² = 104. Each step adds the next perfect square (1, 4, 9, 16, 25, 36). The missing number after 27 is 27 + 16 = 43.

Multiple choice
  1. 3

  2. 39

  3. 11

  4. 20

  5. 6

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

Analyzing the pattern: 1→3 (×2+1), 3→6 (×2), 6→11 (×2-1), 11→20 (×2-2), 20→39 (×2-1), 39→70 (×2-8). The pattern isn't consistent. Let's try differences: 2, 3, 5, 9, 19, 31. Second differences: 1, 2, 4, 10, 12. 39 breaks the pattern - the terms after 11 should follow ×2-1: 11→21→41. Actually, from 20 the next should be 20×2-3=37, then 37×2-3=71. So 39 is wrong.

Multiple choice
  1. 57

  2. 295

  3. 1088

  4. 3570

  5. 7144

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

The pattern is n × (odd multiplier) + (odd multiplier)²: 7.5 × 5 + 25 = 37.5 ≠ 57. Alternate pattern: ×7 + 19.5, ×5 + 10, ×3 + 203 breaks. Pattern 57 × 5 + 10 = 295, 295 × 5 + 10 = 1485 ≠ 1088. 1088 breaks the multiplicative pattern that fits other terms.

Multiple choice
  1. 7

  2. 16

  3. 27

  4. 40

  5. 46

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

Check the pattern: 7 to 16 (+9), 16 to 27 (+11), 27 to 40 (+13), 40 to 46 (+6). The pattern of odd numbers 9, 11, 13 should continue with +15, giving 55, not 46. Therefore 46 is the wrong number that breaks the pattern.

Multiple choice
  1. 577

  2. 798

  3. 627

  4. 543

  5. 696

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

Analyze the number series: 543, 577, 627, 696, 791. Calculate differences: 577-543=34, 627-577=50, 696-627=69, 791-696=95. The differences are 34, 50, 69, 95. Second differences: 50-34=16, 69-50=19, 95-69=26. The pattern 16, 19, 26 is inconsistent. If 627 were 626, the differences would be 34, 49, 70, 95, giving second differences of 15, 21, 25 - still irregular but 627 breaks the expected pattern more noticeably.

Multiple choice
  1. 32

  2. 48

  3. 64

  4. 72

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

The series alternates between cubes of natural numbers and their squares: 1³, 1², 2³, 2², 3³, 3², 4³, 4²... The pattern is (1,1), (8,4), (27,9), (64,16)... where each pair is (n³, n²). The missing term is 4³ = 64, which comes before 16 (which is 4²).