Question

The 4th and 7th term of gp is 1/27and 1/729.find the sum of n terms of gp

Answer 1

Hi , there !!!

4th term of GP is = ar³ = 1/ 27


7th term of GP is ar^6= 1/729


dividing both

we get

r³ = 27

r = 3


ar³ = 1/ 27

a =1/ 81



first nth term will be

ar ^ n -1

=> 1/ 81 × 3 ^ n-1

=> 1 / 27 ^ n-1


hope it help you



thanks !!

Ranjankumar

Answer 2

Hi , there !!!

4th term of GP is = ar³ = 1/ 27


7th term of GP is ar^6= 1/729


dividing both

we get

r³ = 27

r = 3


ar³ = 1/ 27

a =1/ 81



first nth term will be

ar ^ n -1

=> 1/ 81 × 3 ^ n-1

=> 1 / 27 ^ n-1


hope it help you



thanks !!

Ranjankumar