gneet TOPIC : sequence and series additional Number of questions are 151

Paper 4 eco detailed solutions

Paper 4 eco detailed solutions

EXERCISE SET 6 A Q.1

Q.1)If a, b, c are in A.P. as well as in G.P. then –

Q.1)If a, b, c are in A.P. as well as in G.P. then –

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Correct

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a, b, c are in A.P.

∴a+c = 2b

⇒ b = (a+c)/2 ---(i)

a, b, c are in G.P.

∴ b^{2} = ac ---(ii)

Reciprocals are 1/a, 1/b, 1/c

∴ 1/a, 1/b, 1/c are in A.P.

∴ a, b, c are also H.P.

Answer : (c)

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