Assign people to different groups using asp.net mvc C#

Question

I want to assign people to different groups based on their scores, from a table called "people" to another table called "grouping"  starting from the highest score. There are 80 people I want the first 20 candidates with the highest score assigned to “Group A”, the next 20 to ” Group B”, the next 20 to ” Group C” and so on. Am using asp.net MVC and C#

 

Database Name : peopleDB

Fields in people table

peopleID

Firstname

Lastname

scoresobtained

Grouping Table

Firstname

Lastname

group

 

 

In my Controller

public ActionResult autoassign()

{

var rc = new peopleDBEntities();

var res = (from p in rc.people

orderby p.scoresobtained descending

select new

{

firstname = p.firstname.ToString(),

lastname = p.lastname.ToString(),

score = f.canditatescores.ToString(),

});

in my controller as shown above, i have retrieved the values from people table from highest scores.(descending) how do iterate to pare them into groups of 20 each.  i do not know how to go about it. so please help. I am using asp.net mvc in C#