Finding the Equivalent Resistance of an Electric Circuit

All resistors here are 10 Ohms. To reduce the circuit to its equivalent resistance, start at the end opposite the source (Emf).
Here are the steps:

Step 1: Add R2 and R3 in SERIES to get a total of 20 Ohms.
Step 2: Add the result of step 1 with R5 in PARALLEL to get 6.7 Ohms.
Step 3: Add the result of step 2 with R4 in SERIES to get 16.7 Ohms.
Step 4: Add the result of step 3 with R6 in PARALLEL to get 6.25 Ohms.
Step 5: Add the result of step 4 with R1 and R7 in SERIES to get 26.25 Ohms.

So the total equivalent resistance of the seven 10 Ohm resistors in the original curcuit is 26.25 Ohms.

For resistors to be in series, they must have the same current flowing through them. All the charge which flows through one resistor MUST flow through the other one. R2 and R3 are in SERIES.
For resistors to be in parallel, they must have the same starting and ending points. R2 and R3 together are in PARALLEL with R5.