I have a problem that I wasn't sure how to do, and I want to see if my reasoning behind getting the answer is correct.

Question

Question: If .0129 mol of N2O4 effuses through a pinhole in a certain amount of time, how much NO would effuse in that same amount of time under the same conditions?

I know that Graham's Law states that "At a given temperature and pressure, the rate of effusion of a gas, in moles per unit time, is inversely proportional to the square root of its molar mass."

Which would mean (MM N2O4)^.5= rate of effusion

(92.02)^.5= 9.5927 mol/unit t
9.5927 mol/unit t / .0129 mol = 5.291 unit t

(MM NO)^.5= rate of effusion
(28.01)^.5= 5.292 mol/unit t
5.292 mol/unit t / x = 5.291 unit t
x= 1.00 mol

Does this seem correct?

I didn't work it through, but, no, it doesn't seem right. First, the molar mass of NO must be closer to 30 than it is to 28.01. Check that.
(r1/r2)=(sqrt M2/sqrt M1)
(0.129 mols/x mols)=(sqrt92.02/sqrt30)
xmol NO=0.129(sqrt92.02/sqrt30)=>??