each of the 3 resistors has 5 K(ohms),and the potential differnce across the circuit is 2 volts,so each resistor will get 2/3V(the six of them as they are connected in parallel)and the V at X is 4/3(as you have 2 resistors before)and 2/3 at Y,so 4/3 - 2/3 = 2/3.
Im not really good at explaining but i hope you get it