Answer
(p → ~r) ↔ q
Work Step by Step
p: The lines go down.
q: The transformer blows.
r: We have power.
If the lines go down, we do not have power if and only if the transformer blows.
The symbolic representation is:
(p → ~r): If the lines go down, we do not have power.
(p → ~r) ↔ q: If the lines go down, we do not have power if and only if the transformer blows.