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Question
If a, b, c are in A.P,; b, c, d are in G.P and ` 1/c, 1/d,1/e` are in A.P. prove that a, c, e are in G.P.
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Solution
It is given that a, b, c are in A.P.
∴ b – a = c – b … (1)
It is given that b, c, d, are in G.P.
∴ c2 = bd … (2)
Also ` 1/c, 1/d,1/e` are in A.P.
Thus, a, c, and e are in G.P.
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