Help me to understand basic circuit analysis solution

[General_Sax]

Homework Statement

given in uploads.

Homework Equations

The Attempt at a Solution

I just don't understand why they went [(12||6) + 2]

I tried doing (12||8) and I ended up getting the wrong answer.

Why do you have to add the 2k(ohms) to the effective resistance of the 12||6 k(ohms)?

Why couldn't one use 12||8 ?

Another question: Is there any paticular order to calculating the effective resistance?

ie, does one have to work outside -> inside or something similar?

Please and thank you!

 

[skeptic2]

Before beginning to work the problem it helps to redraw the circuit to simplify it, at least in your mind, as in the attachment.

It usually is best to start with the resistances farthest from the source and work back towards the source.

So in the attached circuit do you see why first the parallel combination of the 12k and 6k are calculated and then 2k is added?

 

[General_Sax]

That makes much more sense. Thanks for your time!

 

[evra]

there is a simpler method. i.e;
solve the:
step 1: 2k//6k
step 2: 4k//12
step 3: draw the circuit equivalent whereas u will have the rest in parallel
step 4: u will get exactly 2k