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For what value of k will k + 9, 2k – 1 and 2k + 7 are the consecutive terms of an A.P?

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#### Solution

If k + 9, 2k – 1 and 2k + 7 are the consecutive terms of A.P., then the common difference will be the same.

∴(2k – 1) – (k + 9) = (2k + 7) – (2k – 1)

∴k – 10 = 8

∴k = 18

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