If k, 2k –1 and 2k + 1 are three consecutive terms of an AP, the value of k is

Here A.P = k, 2k –1, 2k + 1


Since the numbers are in A.P their common difference (d) should be same


d=a2–a1 = a3–a2


2k–1–k = 2k + 1– (2k –1)


k– 1 = 2


k = 3

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