Can someone please help... The electric potential difference between two parallel metal plates is delta V. The plates are separated by a distance of 3.0 mm and the electric field between the plates is 350 V/m. Calculate delta V.

Aprisoner is forced to go into one of three rooms, but he can choose which room. the first room is ablaze with fire. the second one is rigged with explosives that will go off as soon as he enters. the third contains a pair of lions who haven't eaten in years. which room should he choose to survive?