A Mixture of Helium, Argon and Krypton Is Made and Stored

Multiple Choice

A mixture of helium, argon and krypton is made and stored in a cylinder at a total pressure of 2.80 atm. The partial pressure of helium is 900 torr, and that of argon is 250 torr. What is the partial pressure of krypton in the mixture?

A) 1.18 atm
B) 1.51 atm
C) 1150 torr
D) 978 torr