as level physics 👍👍👍👍 Watch
series Rtotal = R1 + R2.
parallel 1/Rtotal = 1/R1 + 1/R2
so for W you'd first solve the parallel pair on the right to find the equivalent single resistor...then you'd solve that resistor in series with the single resistor on the left.
when you have the totals for W-Z you can rank them in ascending order.