NEED HELP WITH CHEMISTRY!!

A mixture of 0.166 moles of C is reacted with 0.117 moles of O2 in a sealed, 10.0 L vessel at 500 K, producing a mixture of CO and CO2. The total pressure is 0.640 atm. What is the partial pressure of CO?
3 C(s) + 2 O2 (g) --> 2 CO(g) + CO2(g)
I tried putting 0.43 and 0.427 and it keeps telling me it's incorrect? I REALLY NEED HELP!

PV = nRT

(0.64)(10) = n(0.082)(500)

n = 0.156098 moles


Let x is reacted moles of C,

moles of CO = 2x/3

moles of CO2 = x/3

unreacted moles of O2 = 0.117 - 2x/3

unreacted moles of C = 0.166 - x
- - - - - - - - - - - - - - - - - - - - - - - - - - - - (+)
2x/3 + x/3 + (0.117 - 2x/3) + (0.166 - x) = 0.156098

x = 0.190353 moles

the partial pressure of CO is

P = (2x/3)/0.156098 * P total

P = (2 * 0.190353/3)/0.156098 * 0.64

P = 0.5203 atm