It is given that forward resistance of both diodes D1 and D2 is = 50Ω. It is clear from given circuit diagram that diode D2 is in reverse-bias so it will not conduct. Only diode D1 will conduct as it is in forward-bias.
∴ Total resistance of circuit (R) = 50 + 150 + 100
or R = 300 Ω
So the current flowing through 100 Ω
I = \(\frac{V}{R}=\frac{6}{300}\) = 0.02 A