SELECT count(*) ,  T1.name FROM projects AS T1 JOIN assignedto AS T2 ON T1.code  =  T2.project WHERE T1.hours  >  300 GROUP BY T1.name
What are the names of projects that require more than 300 hours, and how many scientists are assigned to each?
[Schema (values) (types)]: | scientist_1 |  Scientists : ssn (text) , name (number) | Projects : code (text) , name (number) , hours (text) | AssignedTo : scientist (text) , project (number);