Question

Which term of gp 4,2,1.... will be 1/128?

Answer 1

4, 2, 1 , ...........1/128
common ratio of given GP = 2/4 = 1/2
we know,
$T_n=ar^{n-1}$
where, Tn shows nth term of GP series
a is the first term and n is the number of terms .

$now, \frac{1}{128}=4[\frac{1}{2}]^{n-1}$
$\frac{1}{2^7}=\frac{4}{2^{n-1}}$
2^7 × 4 = 2^(n-1)
2^9 = 2^(n-1)
9 = n -1
n = 10

Answer 2

this is the following answer . may it help you