The pressure in the chamber is (c) 258 torr.
According to Dalton's Law of Partial Pressures, each gas will exert its own partial pressure in the chamber.
Since the temperature is constant, we can use Boyle's Law to calculate the partial pressure of each gas in the chamber.
The formula for Boyle's Law is
Step 1. Calculate the partial pressure of neon in the chamber.
Boyle's Law can be rearranged to
Step 2. Calculate the partial pressure of helium in the chamber.
3. Calculate the total pressure in the chamber.
The pressure in the chamber is 248 torr.