Hi Shilps--
The difficulty level of Grockit questions is divided into easier, moderate, and harder. Easier questions are worth 2 or 4 points; moderate questions are worth 8 points; harder questions are worth 16 or 32 points. The difficulty level of the questions adjusts itself based on what percent of users answer a given question correctly. While the majority of our questions are easier or moderate, there are hundreds of questions in the harder range, and Grockit offers users the option of customizing their practice to focus exclusively on a specific difficulty level.
I hope this helps answer your question!

Dear andrea,

Thank you very much for your detailed reply.
Yes, I am very much happy with Grockit and I have taken standard membership.
This is really the best way to keep one engaged for studying.

Thanks and Regards,
Shilps