Find the 4th term from the end of the G.P. `1/2,1/6,1/(18),1/(54), ,1/(4374)`

Explanation

Given,`a=1/2, r=1/3`
​
`T_n​=ar^(n−1)=1/(4374)`
​
​`⇒1/2​(1/3)^(n−1)=1/(4374)`
​​
`=(1/3​)^(n−1)=1/2187`
​

On compairig the powers ⇒n−1=7
​
⇒n=8
​
4th term from end = 8−4+1=5th
​term from beginning
...