Q1 of 50 Page 1

If k, 2k - 1 and 2k + 1 are three consecutive terms of an A.P., the value of k is

The given three consecutive terms of AP are k, 2k – 1 and 2k + 1.


We know that if a, b and c are in AP, then 2b = a + c.


⇒ 2 (2k – 1) = k + 2k + 1


⇒ 4k – 2 = 3k + 1


⇒ 4k – 3k = 1 + 2


⇒ k = 3


∴ The value of k is 3.

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