Question

How many terms of the G.P.
2/9, -1/3, 1/2------- must be added to get the sum equal to 55/72.​

Answer 1

Step-by-step explanation:

Given GP is

2/9 , -1/3 , 1/2 ............

here common difference is (-1/3)/(2/9) i.e. -3/2

and first term is 2/9

Let sum of n terms be 55/72.

Then,

55/72 = (2/9) [ (-3/2)^(n-1) - 1 ] / [(-3/2) -1]

Solve this to get your answer