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 numbers are in G.P. are `a, ar, ar^2`


Given,


`a+ar+ar^2=56`


`a(1+r^2+r)=56`` \ \ \ (1)`


`a-1, ar-7, ar^2-21` are in A.P.


`2ar-14=a-1+ar^2-21`


`a(1-2ar+r^2)=8`


`a(1-r)^2=8`` \ \ \ (2)`


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