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Question -

Insert two numbers between 3 and 81 so that the resulting sequence isG.P.



Answer -

Let’s assume G1 and G2 tobe two numbers between 3 and 81 such that the series 3, G1G2,81 forms a G.P.

And let a bethe first term and r be the common ratio of the G.P.

Now, we have the 1st termas 3 and the 4th term as 81.

81 = (3) (r)3

r3 = 27

 r =3 (Taking real roots only)

For r =3,

G1 = ar = (3) (3) = 9

G2 = ar2 = (3) (3)2 =27

Therefore, the twonumbers which can be inserted between 3 and 81 so that the resulting sequencebecomes a G.P are 9 and 27.

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