Mentors Eduserv is a great way to know and resolve your common mistakes. I personally feel it is a great step towards helping students like me who aim to be in the IITs
Mentors Eduserv comes with topic-wise examples and sample tests for every topic. The solved examples are the best to understand tricky concepts. This is surely a great tool for IIT aspirants
The best thing about Mentors Eduserv is that the mentors are available always with their sound and expert advice. This helped my son, Gaurav, a great deal as he always had someone to talk to when in doubt.