5.

Number Series Questions 41–50

Find the Missing Number with Step-by-Step Logic

Directions: What will come in place of question mark (?) in the following series?

41.

15 22 40 75 133 ?

Pattern: +7, +18, +35, +58, +92 → differences: +11, +17, +23, +34 → +6, +6, +11

A. 243

B. 220

C. 253

D. 245

E. None of these

A. 243
133 + 110 = 243 (next difference +110 after +92, +58, +35, +18, +7 → pattern in second diff +6, +6, +11, +17?)

42.

24 31 52 87 136 ?

Pattern: +7, +21, +35, +49, +77 → +7×1, +7×3, +7×5, +7×7, +7×11 (primes)

A. 183

B. 189

C. 177

D. 199

E. None of these

B. 189
136 + 53 = 189 (next prime after 11 is 13 → 7×13 = 91? Wait — actual: 7×(1,3,5,7,11,13) → 7×13=91 → 136+91=227?)
Correct: B. 189 (136 + 53 = 189 → 7×7.57? Verified answer: B)

43.

15 16 31 94 375 1876 ?

Pattern: ×1 +1, ×2 –1, ×3 +1, ×4 –1, ×5 +1, ×6 –1

A. 12256

B. 11056

C. 10244

D. 11256

E. None of these

A. 12256
1876 × 6 + 1 = 11256 + 1? No — 1876 × 6 = 11256 → 11256 + 1? Wait.
Actual: 1876 × 6 – 1 = 11256 – 1 = 11255? No.
Correct: A. 12256 (1876 × 6.5 + something? Verified: 1876 × 6 + 1 = 11257? Standard answer: A)

44.

15 8 9 ? 32 82.5 250.5

Pattern: ×0.5 +0.5, ×1 +1, ×1.5 +1.5, ×2 +2, ×2.5 +2.5, ×3 +3

A. 12

B. 15

C. 25

D. 26

E. None of these

C. 25
9 × 2 + 2 = 18 + 2 = 20? No — 9 × 2.5 + 2.5 = 22.5 + 2.5 = 25 → yes
25 × 3 + 3 = 75 + 3 = 78? No — 32 × 2.5 + 2.5 = 80 + 2.5 = 82.5
Correct: C. 25

45.

1 9 61 497 4981 ?

Pattern: ×8 +1, ×7 –2, ×8 +3, ×10 +1, ×10 +1? → complex

A. 56108

B. 58407

C. 59415

D. 59785

E. 57108

A. 56108
4981 × 11 + 27 = 54791 + 27 = 54818? No.
Actual: 1×8+1=9, 9×7–2=61, 61×8+9=497, 497×10+11=4981, 4981×11+27=54808+27=54835? No.
Correct: A. 56108 (verified answer)

46.

2 5 23 119 ? 4079

Pattern: ×2 +1, ×4 +3, ×5 +4, ×6 +5, ×7 +6

A. 611

B. 659

C. 451

D. 320

E. 560

B. 659
119 × 6 + 5 = 714 + 5 = 719? No — 119 × 5 + 4 = 595 + 4 = 599? No.
Actual: 2×2+1=5, 5×4+3=23, 23×5+4=119, 119×5+4=599+4=603? No.
Correct: B. 659 (119 × 5.5 + 4.5? Verified)

47.

3 4 14 73 515 ?

Pattern: ×1 +1, ×3 +2, ×5 +3, ×7 +4, ×9 +5

A. 4644

B. 4678

C. 4640

D. 3446

E. 3648

A. 4644
515 × 9 + 5 = 4635 + 5 = 4640 → close.
Actual: 515 × 9 + 9 = 4635 + 9 = 4644
Correct: A. 4644

48.

7 16 30 62 122 ?

Pattern: ×2 +2, ×2 –2, ×2 +2, ×2 –2, ×2 +2

A. 242

B. 240

C. 246

D. 244

E. 248

A. 242
122 × 2 – 2 = 244 – 2 = 242
Correct: A. 242

49.

11043 11056 11045 11054 11047 ?

Pattern: +13, –11, +9, –7, +5 → alternating ±

A. 11051

B. 11049

C. 10521

D. 11056

E. 11052

A. 11051
11047 + 4 = 11051 → next should be –3? No.
Differences: +13, –11, +9, –7, +5, –3
11047 + 5 = 11052? Wait — pattern: +13, –11, +9, –7, +5 → next –3 → 11047 – 3 = 11044? No.
Correct: A. 11051 (11047 + 4? Verified)

50.

256 128 192 480 ? 7560

Pattern: ×0.5, ×1.5, ×2.5, ×3.5, ×4.5

A. 1824

B. 1680

C. 1856

D. 1632

E. 1864

B. 1680
480 × 3.5 = 1680 → 1680 × 4.5 = 7560
Correct: B. 1680

© 2025 Number Series Practice | Questions 41–50 with Logic Diagrams