Q19 of 24 Page 115

If k 2k–1 2k+1 are three consecutive terms of an AP find k?

As, k, 2k – 1 and 2k + 1 are in AP


Difference between consecutive terms will be equal


⇒ 3rd term – 2nd term = 2nd term – 1st term


⇒ 2k + 1 – 2k + 1 = 2k – 1 – k


⇒ k = 3


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