Study hours

akash vig ( IPCC STUDENT) (79 Points)

12 September 2013  
I m really struggling about study hrs.... Yesterday i heard someone say dat he studies 18 hrs daily.. (i was really shocked) .....I know every1 says that it doesn't matter how much time u put in but what matters is the efficiency. .. but still I feel that there must be some minimum hrs to be devoted daily.. so plz help me as to how much hrs to be put in daily ??