How I Convert This query from sql to linq-to-entity in Asp.net

SELECT [Problem_Name] ,[Lab_Name], COUNT(*) count_problem
  FROM [laboratory].[dbo].[Problem_tab]p,
  [laboratory].[dbo].[PC_Hard_Problem_tab] pp,[laboratory].[dbo].[Lab_tab] l
  WHERE  p.Problem_Id = pp.Problem_Id AND l.Lab_Id = 8
  GROUP BY p.Problem_Id,Problem_Name,[Lab_Name];