The resistor R2 is attached is parallel to the resistor R1 and both of them have a voltage source of 10 V acting across them. There is no relation between the current flowing through the two resistors as they are connected in parallel to the voltage source.
The current I that passes though a resistor R when a voltage V is applied is equal to I = V/R.
There is a current of 10 m A flowing through the resistor R2. This gives the resistance of R2 as 10/(10*10^-3) = 1*1000 = 1000 ohm
The resistance of R2 is 1 k ohm.