Sir may I ask why can’t we find the combined resistance of the three resistors 12ohm,4ohm and 6 ohm directly, instead of finding 12&4 first then 3&6 separately? Thanks and i hope you will help.
But then probably one will have to use the basic formula of solving parallel resistance, for easier calculation...that is...1/ Req = 1/ R1 + 1/ R2 + 1/ R3