When the resistance is connected in series then the formula of equivalent resistance, R=R1+R2+R3+....+Rn, but when they are connected in parallel then net resistance is, R1=R11+R21+R31+...+Rn1, so in the above diagram the equivalent resistance will be,
,
in the above branch, resistance are connected in parallel, so new equivalent resistance will be,

So, the final resistance will be, Rnet=(4+4+8)Ω=16Ω.
