LINQ Query - Collapse Two Rows Into One

Using a LINQ query and an aspx page with an Infragistics webdatagrid control, I am generating data that look like this:The data come from my dataset: There is another column which is TobaccoUse and it is N, Y, N, Y, N, Y, etc for each row. There is also a column for the rate, and it is 147.32 for all rows (test data). But it could and most likely will, especially as the ages increase, be different, like $250 for a 25-year-old smoker but $200 for a 25-year-old non-smoker.

The grid I want to present needs to collapse every two rows into one, so you see one row for 0-17 smoker and non-smoker, etc. I do not know how to write this query. I don't actually know how to write any LINQ query but I've enhanced some existing ones, or understood them, but it's easier to read something that exists than write it new or change it dramatically, which I believe I need to do.

The query right now is:

Code:
var medRateBook = from rates in dsMedRateBookRates.Tables[0].Rows.Cast<DataRow>()
select new
{
DivisionNum = div.DivisionNbr.Trim(),
Age = rates["agedesc"].ToString().Trim(),
TobaccoRate = rates["calcratePreferred"].ToString().Trim(),

[code]....