Question

In a G.P the 9th term is 32805 and 6th term is 1215. Find the 12th term.​

Answer 1

Answer:

885735

Step-by-step explanation:

In a G.P the 9th term is 32805 and 6th term is 1215. Find the 12th term.​

Let say GP's First Term = a  & common ratio = r

Then 9th Term = ar⁸  = 32805

& 6th term = ar⁵ = 1215

=> ar⁸ /ar⁵ = 32805 /1215

=> r³ = 27

=> r = 3

ar⁵ = 1215

=> a3⁵ = 1215

=> a * 243 = 1215

=> a = 5

12th term = ar¹¹ = 5 * 3¹¹  = 5 * 177147 =  885735

Answer 2

Hey there!

Answer:

T₁₂= 885735

Step-by-step explanation:

Given,

9th term = 32805

T₉ = 32805

ar⁸ = 32805 ............(i)

And, 6th term = 1215

T₆ = 1215

ar⁵ = 1215 ............(ii).

Dividing equation (i) by (ii):

ar⁸ / ar⁵ = 32805 / 1215

r³ = 27

r = 3.

Now, putting value of r in eq. (ii).

ar⁵ = 1215

a * 3⁵ = 1215

a * 243 = 1215

a = 1215 /  243

a = 5.

Now,

12th term

= ar¹¹ = 5 * 3¹¹

T₁₂= 885735