I have managed to do all parts in the question except part d. I am stuck at part d.
The way I have tried is the following: On the non-inverting lead of the op amp, there is a Voltage offset sources attached along with a resister to compensate for the bias current. I used superposition. First I replace the bias current source inside the op amp with an open circuit and so the voltage seen by positive terminal of the op amp is Vos. And then I replace the Vos with a short circuit and also find output voltage. But my answer is not correct. The correct answer for part d is 22mV. Can someone tell me how to solve for part d?