Number and letter series
Ten reasoning questions, each marked as you answer.
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Which number replaces the question mark? 79, 83, 89, 97, 101, 103, ?
Answer and working
Answer B
The rule: consecutive prime numbers. The missing term is 107.
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Which pair comes next? GX, HU, IR, JO, ?
Answer and working
Answer B
The first letters move forward 1 (G, H, I, J); the second move back 3 (X, U, R, O). Next: KL.
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Which number replaces the question mark? 89, 97, 101, 103, 107, 109, ?
Answer and working
Answer C
The rule: consecutive prime numbers. The missing term is 113.
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Which pair comes next? EW, FV, GU, HT, ?
Answer and working
Answer D
The first letters move forward 1 (E, F, G, H); the second move back 1 (W, V, U, T). Next: IS.
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Which number replaces the question mark? 4, 8, 16, 32, 64, ?
Answer and working
Answer A
The rule: each term is the previous × 2. The missing term is 128.
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Which group comes next? EFG, KLM, QRS, ?
Answer and working
Answer D
Inside each group the letters step by 1; each group starts 6 letters after the last (E, K, Q). Next: WXY.
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Which number replaces the question mark? 0, 3, 8, 15, 24, 35, ?
Answer and working
Answer B
The rule: the terms are 1², 2², 3² … minus 1. The missing term is 48.
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Which group comes next? GIK, KMO, OQS, ?
Answer and working
Answer A
Inside each group the letters step by 2; each group starts 4 letters after the last (G, K, O). Next: SUW.
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Which number replaces the question mark? 23, 29, 31, 37, 41, 43, ?
Answer and working
Answer B
The rule: consecutive prime numbers. The missing term is 47.
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Which pair comes next? AZ, BX, CV, DT, ?
Answer and working
Answer D
The first letters move forward 1 (A, B, C, D); the second move back 2 (Z, X, V, T). Next: ER.
More reasoning: Coding and decoding, Analogies, Odd one out, Blood relations, Direction sense, Seating in a row.