Question

the 3rd and 6 th term of GP are 3 and 81 . what is the first term and what is the common ratio of thr sequence??

Answer 1

Hii friend,

a+2d = 3........(1)

a+5d = 81.......(2)

From equation (1) we get,

a+2d = 3

a = 3-2d.......(3)

Putting the value of a equation (2)

a+5d = 81

(3-2d) + 5d = 81

3d = 81-3

d = 78/3

d = 26

Putting the value of D in equation (3)

a = 3-3d

a = 3-3 × 26

a = 3 - 78

a = -75


Hence,

First term = -75

And,

Common difference = 26


HOPE IT WILL HELP YOU....... :-)