There is a really big jump from Grade 9 to 10. 2 hours a day would be the minimum to complete it in the time frame, but it should be possible. As to the 85%, it's impossible to say whether you could achieve this as I do not know your practice habits. Why the set time frame?My repetoire for June exam is:Bach Fantasia in C MinorMozart Sonata in Eflat MajorSchubert Moment muscial op 94 no 2Rachmaninoff Prelude op 32 no 10Oscar Peterson Land of the Misty Giants.You should, however, pick the repetoire YOU like.FYI - I have been working on Grade 10 for two years, but I dropped some pieces along the way, did not play for 25 years before returning and have difficulty being consistent with practice due to family and work commitments. Age is also making memorization a real issue. I am participating in a local music festival this spring, so I will see how I am doing...