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NDA2018MathematicsSequences and SeriesActual

If a, b, c are in AP or GP HP, then a-b b-c is equal to

Options

  1. Ab a or 1 or b c
  2. Bc a or c b or 1
  3. C1 or a b or a c
  4. D1 or a b or c a

Correct answer

C. 1 or a b or a c

Step-by-step solution

From question, aligned & a, b, c A.P. a-b=b-c a-b b-c =1 & a, b, c G.P. a b = b c = a-b b-c & a, b, c H.P. b= 2 a c a+c a b+b c=2 a c & a b-a c=a c-b c & a-b b-c = a c aligned

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