Series
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.AB, CD, EF, GH, ? Answer: C. IJ Answer: (C) IJ Consecutive pairs of letters: AB, CD, EF, GH, then IJ. 1
- Select the number that can replace the question mark (?) in the following series.2, 5, 11, 23, 47, ? Answer: C. 95 Answer: (C) 95 Rule: ×2 + 1. 2×2+1 = 5, 5×2+1 = 11, 11×2+1 = 23, 23×2+1 = 47. Next: 47 × 2 + 1 = 95. 1
- Select the number that can replace the question mark (?) in the following series.4, 6, 10, 16, 24, ? Answer: A. 34 Answer: (A) 34 The differences are 2, 4, 6, 8, so the next difference is 10. 24 + 10 = 34. 1
- Select the number that can replace the question mark (?) in the following series.7, 8, 12, 21, 37, ? Answer: D. 62 Answer: (D) 62 The differences are 1, 4, 9, 16, that is 1², 2², 3², 4² . Next difference = 5² = 25 , so 37 + 25 = 62. 1
- Select the number that can replace the question mark (?) in the following series.6, 13, 27, ?, 111 Answer: D. 55 Answer: (D) 55 Rule: ×2 + 1. 6×2+1 = 13, 13×2+1 = 27, so the missing term is 27×2+1 = 55. Check: 55×2+1 = 111. ✓ 1
- Find the wrong number in the following series.1, 3, 7, 15, 32, 63 Answer: D. 32 Answer: (D) 32 Rule: ×2 + 1 (or 2ⁿ - 1 ): 1, 3, 7, 15, 31, 63. The term 32 should be 15 × 2 + 1 = 31, so 32 is wrong. 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.B, E, I, N, ? Answer: A. T Answer: (A) T Positions: B = 2, E = 5, I = 9, N = 14. The gaps are +3, +4, +5. Next gap +6: 14 + 6 = 20 = T. 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.AZ, BY, CX, ?, EV Answer: B. DW Answer: (B) DW The first letters go A, B, C, D, E (+1). The second letters go Z, Y, X, W, V (−1). So the missing term is DW. 1
- Select the number that can replace the question mark (?) in the following series.120, 99, 80, 63, 48, ? Answer: C. 35 Answer: (C) 35 120 = 11² - 1 , 99 = 10² - 1 , 80 = 9² - 1 , 63 = 8² - 1 , 48 = 7² - 1 . Next: 6² - 1 = 35 . (Or: the differenc... 1
- Select the number that can replace the question mark (?) in the following series.2, 3, 4, 9, 8, 27, 16, ? Answer: A. 81 Answer: (A) 81 Two series are mixed. Odd places: 2, 4, 8, 16 (×2). Even places: 3, 9, 27 (×3). The missing term is in the even... 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.DKM, FJN, HIO, ? Answer: D. JHP Answer: (D) JHP First letters: D, F, H, J (+2). Second letters: K, J, I, H (−1). Third letters: M, N, O, P (+1). So the next... 1
- Select the number that can replace the question mark (?) in the following series.1, 2, 6, 24, 120, ? Answer: A. 720 Answer: (A) 720 Multiply by 2, 3, 4, 5: 1×2 = 2, 2×3 = 6, 6×4 = 24, 24×5 = 120. Next: 120 × 6 = 720. 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.ACE, GIK, MOQ, ? Answer: D. SUW Answer: (D) SUW Inside each cluster the letters go +2 (A, C, E). Each cluster starts 6 letters after the previous one: A, G,... 1
- Select the number that can replace the question mark (?) in the following series.3, 4, 10, 33, 136, ? Answer: B. 685 Answer: (B) 685 Rule: ×1 + 1, ×2 + 2, ×3 + 3, ×4 + 4, ... 3×1+1 = 4, 4×2+2 = 10, 10×3+3 = 33, 33×4+4 = 136. Next: 136 × 5 + 5... 1
- Select the number that can replace the question mark (?) in the following series.2, 3, 11, 38, 102, ? Answer: C. 227 Answer: (C) 227 The differences are 1, 8, 27, 64, that is 1³, 2³, 3³, 4³ . Next difference 5³ = 125 : 102 + 125 = 227. 1
- Find the wrong number in the following series.3, 5, 9, 17, 33, 65, 128 Answer: B. 128 Answer: (B) 128 Rule: ×2 − 1. 3→5→9→17→33→65. After 65 the term should be 65 × 2 − 1 = 129, so 128 is wrong. 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.C3, F6, J10, O15, ? Answer: B. U21 Answer: (B) U21 In each term the number is the position of the letter: C = 3, F = 6, J = 10, O = 15. The positions go +3, +4,... 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.Z1A, X2D, V6G, T21J, ? Answer: A. R88M Answer: (A) R88M First letters: Z, X, V, T, R (−2). Last letters: A, D, G, J, M (+3). Numbers: 1×1+1 = 2, 2×2+2 = 6, 6×3+3 =... 1
- Select the number that can replace the question mark (?) in the following series.3, 7, 11, 15, ? Answer: B. 19 Answer: (B) 19 Each term is 4 more than the previous one: 15 + 4 = 19. 1
- Select the number that can replace the question mark (?) in the following series.2, 6, 18, 54, ? Answer: A. 162 Answer: (A) 162 Each term is 3 times the previous one: 54 × 3 = 162. 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.A, C, E, G, ? Answer: C. I Answer: (C) I The letters skip one each time (+2): A, C, E, G, I. 1
- Select the number that can replace the question mark (?) in the following series.1, 4, 9, 16, 25, ? Answer: D. 36 Answer: (D) 36 The terms are 1², 2², 3², 4², 5² . Next is 6² = 36 . 1
- Select the number that can replace the question mark (?) in the following series.100, 95, 85, 70, ? Answer: C. 50 Answer: (C) 50 The differences are −5, −10, −15, so next is −20: 70 − 20 = 50. 1
- Select the letter or letter-cluster that can replace the question mark (?) in the following series.Z, X, V, T, ? Answer: A. R Answer: (A) R The letters go back two places each time: Z, X, V, T, R. 1