Chemistry ICE Table Help?

[Mi]

I am having a hard time figuring out how to set up the I-C-E Table to this chemistry problem.

Hydrogen Iodide can decompose into hydrogen and iodide gases.

If 0.820atm HI(g) is sealed in a flask, what is the pressure of each gas when equilibrium is established?

2HI(g) <---> H2(g) + I2(g)


My teacher told plug in what we know from the I-C-E Table, but when it says 0.820 atm HI does that mean initial for 2HI? I am also having a hard time finding where to put X's in the table in preparation for the K=Formula.

All I have set up so far on the ICE table is the initial atm for the three compounds ( HI = 0.820, H2 = 0 and I2 = 0 )

Besides that I don't know how to determine what is x, 2x, 1/2x 1-1/2x and stuff like that.. I know you have to look at the ratio of moles in 2HI(g) <---> H2(g) + I2(g), but I am having a hard time doing that as well....

The answer is: HI=0.645 atm H2 = 0.083 I2= 0.083 atm

I don't know how to figure this out if someone could help me that would be greatly appreciated..

P.S. - If there is a way to do this problem without an ICE table I cannot do it because we have to show an ICE table on the test in order to get partial credit for our answer.
*****The Kp = 0.016 Sorry I did not post that the first time******