1. Example: calculate the equivalent resistance of the resistor “ladder” shown. All resistors have the same resistance R.
I’ll work this “conceptually. A B
Here’s the key to solving Physics problems: don’t bite off more than you can chew. Bite off little bite-sized chunks.

2. A hot dog. Where do you take the first bite?

3. Not a “law” of physics, but sometimes helps with circuits: look for “bite-sized” chunks sticking out at one end.
Series A B

4. Any more bite-sized chunks?
The new color indicates the value of the resistance is not R. In a real problem, you would calculate the “new color” resistor’s resistance.
Parallel A B
Any more bite-sized chunks?

5. Series A B

6. Parallel A B

7. Series A B

8. All done! A B