Solving Diode Logic Circuits: 4V, B=2V, C=3V

[Dirac8767]

EDIT: I was being stupid and forgot the first diode would turn off after i worked out stuff for diode C, thanks anyway, solution found!Hi I'm having some trouble getting the correct output voltage when i model the diodes using a voltage ofset and resistors.

A = 4V, B = 2V, C = 3V
Using Voltage drop across the diode of 0.7V and a on resistance of 500 ohms

Doing the analysis of the circuit in the attachments I conclude A & C are on.

I₁ = I₂ + I₃

I₁ = (5 - V_x)/1500

I₂ = (V_x- 4.7)/500

I₃ = (V_x- 3.7)/500

Once i re-arrange all of those i get Vout to be 4.31V whereas in the answers it should be 4.03V.

Any help would be gratefully received! many thanks

Edit: Vx is the node all the diodes are attached to

 

[reddvoid]

only diode C will be ON