the sum of three numbers in G.P. is 56. If we subtract 1,7,21 from these numbers in that order then we obtain an A.P. the three numbers is

Explanation

Let the three numbers in G.P. be ` a,ar and ar^2`


From the given condition


`a+ar+ar^2=56⇒a(1+r+r^2)=56...(1)`


Also given `a−1,ar−7,ar^2−21 `forms an A.P.


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