Now I am sure that the solution of the 1st part is correct and I have solved the 2nd part also. In the 2nd case,  as the ascending surface is also frictionful, so the marble will be pure rolling and both its translational and rotational velocities will become zero when it reaches its max. height. So, all the K.E. is lost thus

 

              loss in K.E. = 7/10 mr²w² 

This is gained as P.E.

So,     mgH = 7/10 mr²w²

                  H = 7/10 . 10h/7

       So,   H= h