Aa, R_1 and R_2 are in parallel so,
1/R_a = 1/R_1 +R_2 = 1/6 + 1/3 = 1/2
R_a =2 Ω
R_6 and R_7 are in parallel,
R_b = 1/R_6 + 1/R_7 = 1/1 + 1/x = x +1 /x
R_b = x /x+1 Ω

R_3 and R_4 are in series ,
then R_c =R_3+R_4 = 1+ 2 = 3 Ω.
Using Wheatstone bridge principle, P/Q = R/S

2/3 = x/x+1 /x
x =1/2 Ω.
As x = 1/n = 1/2 Ω. So, n = 2
Aa, R_1 and R_2 are in parallel so,
1/R_a = 1/R_1 +R_2 = 1/6 + 1/3 = 1/2
R_a =2 Ω
R_6 and R_7 are in parallel,
R_b = 1/R_6 + 1/R_7 = 1/1 + 1/x = x +1 /x
R_b = x /x+1 Ω

R_3 and R_4 are in series ,
then R_c =R_3+R_4 = 1+ 2 = 3 Ω.
Using Wheatstone bridge principle, P/Q = R/S

2/3 = x/x+1 /x
x =1/2 Ω.
As x = 1/n = 1/2 Ω. So, n = 2
Aa, R_1 and R_2 are in parallel so,
1/R_a = 1/R_1 +R_2 = 1/6 + 1/3 = 1/2
R_a =2 Ω
R_6 and R_7 are in parallel,
R_b = 1/R_6 + 1/R_7 = 1/1 + 1/x = x +1 /x
R_b = x /x+1 Ω

R_3 and R_4 are in series ,
then R_c =R_3+R_4 = 1+ 2 = 3 Ω.
Using Wheatstone bridge principle, P/Q = R/S

2/3 = x/x+1 /x
x =1/2 Ω.
As x = 1/n = 1/2 Ω. So, n = 2