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Question -

Insert 6 geometric means between 27 and 1/81.



Answer -

Let the six terms be a1,a2, a3, a4, a5, a6.

A = 27, B = 1/81

Now,┬аthese 6terms are between A and B.

So the GP is: A, a1,a2, a3, a4, a5, a6, B.

So we now have 8 termsin GP with the first term being 27 and eighth being 1/81.

We know that,┬аTn┬а=arnтАУ1

Here, Tn┬а=┬а1/81,a = 27 and

1/81 = 27r8-1

1/(81├Ч27) = r7

r = 1/3

a1┬а=Ar = 27├Ч1/3 = 9

a2┬а=Ar2┬а= 27├Ч1/9 = 3

a3┬а=Ar3┬а= 27├Ч1/27 = 1

a4┬а=Ar4┬а= 27├Ч1/81 = 1/3

a5┬а=Ar5┬а= 27├Ч1/243 = 1/9

a6┬а=Ar6┬а= 27├Ч1/729 = 1/27

тИ┤┬аThe six GMbetween 27 and 1/81 are 9, 3, 1, 1/3, 1/9, 1/27

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