Can you help me with Chemistry? Part 4?

Question

A mixture of three gases, A, B, and C, is at a total pressure of 6.11 atm. The partial pressure of gas A is 1.68 atm; that of gas B is 3.89 atm. What is the partial pressure of gas C?
(Please show work)

Answer 1

Dalton's law of partial pressures. The total pressure of a system of gases is equal to the sum of all the partial pressures of each gas.

Ptotal = P1 + P2 + P3

6.11 atm = 1.68 atm + 3.89 atm + X
6.11 atm = 5.57 atm + X
6.11 atm - 5.57 atm = X
0.54 atm = X

Answer 2

add gas A and B. Then do

6.11 - (gas A+B)=gas C