Question

The third term of a Gp is 3 and sixth term is 81 find its ninth term​

Answer 1

ar2 = 3 _. 1)

ar5 = 81. _. 2)

from 1 &2 ,

r3 = 27

so , therefore r= 3 , put value of r in eq 1 to obtain the value of a

a= 3/r2

a= 3/ 9= 1/3

therefore a9 = ar8 = 1/3* (3)8

= 3 to the power 7