I called them about this. They registered my complaint and they (support team) called me back and they said it is correct.
In the test of definite integration of 2 hours, the topper solved in 25 minutes and they said he did so. It is not fake @Naman
Btw you cant say only wrong. I only noticed 2 in my 2 years. Bhai mujhe to itne naye quality question milte hain physics mein. Overall it is useful to me.