Alphabet & Number Series Previous Year Questions

Explanation

In 69, 81 and 87 both numbers are divisible by 3 (second = first × 7, a multiple of 21). In 67-469 neither 67 nor 469 is divisible by 3, so it is the odd pair.

Explanation

In the other three pairs the letters change alternately by +2 and −1 (e.g. I→K, N→M). In CABALETTA the pattern is −2, +1 (C→A, A→B), so it is different.

Explanation

In the others the second number is 5 times the first (55×5 = 275, 35×5 = 175, 25×5 = 125). 45×5 = 225, not 235.

Explanation

Checking each even number that has an odd number after it and no even number before it gives 13 such numbers.

Explanation

Rounding: 56 ÷ 28 − 68 + 98 × 14 ≈ 2 − 68 + 1372 = 1306. (The exact value is about 1276, and 1306 is still the closest option.)

Explanation

First letters go back by 3 (X, U, R, O, L), second letters go forward by 1 (G, H, I, J, K), and third letters go forward by +1, +2, +3, +4 (C, D, F, I, M). So the next term is LKM.

Explanation

The series has 29 letters, so the 11th from the right is the 19th from the left (J). The 7th letter to its left is the 12th from the left, which is C.

Explanation

In every other pair the second number is 4.5 times the first (16 × 4.5 = 72, 24 × 4.5 = 108, 18 × 4.5 = 81). 22 × 4.5 = 99, not 97, so 22 - 97 is the odd one.

Explanation

Rounding gives 24 ÷ 12 − 77 + 30 × 17 = 2 − 77 + 510 = 435.

Explanation

In every pair the second number is 3 times the first, but in 13, 23 and 17 the first number is prime. 27 is not prime (both 27 and 81 are powers of 3), so 27 - 81 is the odd pair.

Explanation

First letters go N, I, F, A, X (-5, -3, -5, -3, wrapping A to X); second letters R, Y, J, Q, B (+7, +11 alternately); third letters C, N, U, F, M (+11, +7 alternately). Only XBMW fits.

Explanation

The differences are −3, +9, −27, +81, −243 (each multiplied by −3). So 260 − 243 = 17.

Explanation

The differences are 7, 14, 21, 28, so the next difference is 35: 74 + 35 = 109.

Explanation

Round off: 46 − 95 ÷ 19 + 35 × 8 = 46 − 5 + 280 = 321.

Explanation

49 = 7², 64 = 8² and 81 = 9², but 11² = 121, not 120. So 120-11 is the odd pair.

Explanation

50 × 4 − 10 = 190, 46 × 4 − 10 = 174 and 30 × 4 − 10 = 110, but 18 × 4 − 10 = 62, not 72. So 18-72 is different.

Explanation

The pairs are P-O, P-T, P-V, I-E and T-V, which makes 5 pairs. So the answer is more than three.

Explanation

The bottom letter of each figure is the top letter of the figure before it, and the crossed lines alternate. So the next figure has V at the bottom and a new symbol (the arrow) at the top, as in option C.

Explanation

Check each term against its neighbours: 9 (after 9, before 7), 9 (after 3, before 6), 2 (after 2, before 4) and 4 (after 2, before 5) are divisible by the preceding number but not by the following one. That gives four numbers.

Explanation

First letters go P, Q, R, S, T (+1). Second letters go M, O, Q, S, U (+2). Third letters go T, W, Z, C, F (+3). So the next term is TUF.

Explanation

In each pair the second number is 7 times the first: 59 × 7 = 413, 61 × 7 = 427, 47 × 7 = 329. But 37 × 7 = 259, not 269.

Explanation

78.69 + (29.19 × 13.17 ≈ 384.4) − (45.67 ÷ 22.89 ≈ 2) ≈ 461, and 454 is the closest option.

Explanation

Rule: reverse the first three letters and the last three, apply +1, −1, +1 to each group, and keep the middle letter. COMMAND should give NND M EMB = NNDMEMB, but the pair shows NNDMENB. The other three pairs follow the rule.

Explanation

Rule: shift each letter +1, then swap the letters in each pair. ACTUAL → BDUVBM → DBVUMB, but the given code is DBUVMB. HOTELS → PIFUTM, MATTER → BNUUSF and ACTING → DBJUHO follow the rule.

Explanation

In each pair, second = 3 × first + 2: 19 → 59, 17 → 53, 23 → 71. For 29, 3 × 29 + 2 = 89, not 91.