Question

312,311,307,298,?,257​

Answer 1

Answer:

278

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Answer 2

282

Step-by-step explanation:

312,311,307,298,___,257

$312 - 311 = 01 \\ 311 - 307 = 04 \\ 307 - 298 = 09 \\ 298 - (282) = 16 \\ (282) - 257 = 25 \\ first \: see \: all \: terms \: their \: answer \\ 1 + 3 = 4 \\ 1 + 3 + 5 = 9 \\ 1 + 3 + 5 + 7 = 16 \\ 1 + 3 + 5 + 7 + 9 = 25$

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