Since the temperature of the gas remains constant in the process, we can use Boyle's law, which states that for a gas transformation at constant temperature, the product between the gas pressure and its volume is constant:
which can also be rewritten as
(1)
where the labels 1 and 2 mark the initial and final conditions of the gas.
In our problem,
, 
and 
, so the final pressure of the gas can be found by re-arranging eq.(1):
Therefore the correct answer is
<span>1. 0.75 atm</span>
which can also be rewritten as
where the labels 1 and 2 mark the initial and final conditions of the gas.
In our problem,
Therefore the correct answer is
<span>1. 0.75 atm</span>
