Answer:
2 atm
Step-by-step explanation:
Ideal gas law:
PV = nRT
where P is absolute pressure,
V is volume,
n is number of moles,
R is gas constant,
and T is absolute temperature.
If n, R, and T are held constant:
PV = PV
(1 atm) (3 L) = P (1.50 L)
P = 2 atm